Is Shari`ah Comprehensive?
Question

Does Islamic Shari`ah offer solutions for all issues – political, social and economic – in detail? If there arises an issue to which there is no reference in the Islamic system of law, where do we turn to find an answer?
Praise be to Allah.Is Shari`ah comprehensive?
The Islamic system of law (Shari`ah ) that Allah, may He be Exalted, revealed to His slaves covers all that people need with regard to their creed, their acts of worship, and their interactions with one another, because it is the final religion and system of law, with which the final Prophet (blessings and peace of Allah be upon him) was sent to all people. So there is no prophet after him and no law after his law. Even ‘Isa (peace be upon him), when he comes down at the end of time, will judge in accordance with it.
The one who reflects on the Quran and studies the Sunnah, and examines the books of jurisprudence and novel issues will realise that with certainty.
The rulings are either specifically mentioned in the religious text of the Quran and Sunnah – this is called the fundamental rulings (Usul Al-Ahkam), and most of what people need can be found in these rulings. Or the rulings are not specifically mentioned in the religious texts, but the jurist can find out the ruling concerning a matter by examining other Shar`i evidence, such as the reports reported from the Companions, or analogy (Qiyas) with the rulings mentioned in the text, or Istis-hab (assumption of the continuation of a fact in the absence of proof to the contrary) or Masalih Mursalah (the public interest) or barring means that lead to evil.
Hence Allah, may He be Exalted, says (interpretation of the meaning):
{[Say], “Then is it other than Allah I should seek as judge while it is He who has revealed to you the Book explained in detail?” And those to whom We [previously] gave the Scripture know that it is sent down from your Lord in truth, so never be among the doubters.} [Al-An‘am 6:114]
{And We have sent down to you the Book as clarification for all things.} [An-Nahl 16:89]
In the Hadith it says: “There is no deed that brings a person closer to paradise but I have enjoined it upon you, and there is no deed that brings a person closer to hell but I have forbidden it to you. No one of you should think that his provision is slow in coming, for Jibril inspired to me that one of you will never depart this world until he has received his provision in full. So fear Allah, O people, and be moderate in seeking provision. If any of you think that his provision is slow in coming, let him not seek it by disobeying Allah, for Allah’s bounty cannot be attained by disobeying Him.” (Narrated by Ibn Abu Shaybah in Al-Musannaf, 34332 and by Al-Hakim in Al-Mustadrak, 2/5; classed as authentic by Al-Albani in Sahih At-Targhib wa’t-Tarhib, 1700)
Shaykh Ibn ‘Uthaymin (may Allah have mercy on him) said: 
“Islamic rulings may be divided into two categories:

[The first category] is that which the Lawgiver [Allah] mentioned in specific terms in the religious texts, such as the verses,

{Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah ….} [Al-Ma’idah 5:3]
{And lawful to you are [all others] beyond these.} [An-Nisa’ 4:24] – this refers to women who are permissible to marry.
And there are many examples of that.

The second category is that which is not mentioned in specific terms in the texts; rather it is mentioned in general guidelines in Islamic teachings and general Shar`i evidence. That is because the Islamic system of law is comprehensive and covers everything, but it is not possible to mention every issue specifically in the texts, for that would require many volumes that no vehicles could carry.

But there are general, basic guidelines with which Allah blesses whomever He wills of His slaves, so that they will be able to find answers to other minor issues by means of the general guidelines and rulings, such as, “There should be neither harming nor reciprocating harm,” for example. Even though there are some reservations about the soundness of the Hadith, the basic principles of Islam testify to the soundness of its meaning. This general principle could cover thousands of issues in which there is harm, and thousands of issues in which there is reciprocal harm, without having to mention each issue by name.
For example, at the time of the caliph ‘Umar ibn Al-Khattab (may Allah be pleased with him), there was a dispute between two men. One of them owned two pieces of land, between which there was a piece of land belonging to another man. The owner of the two pieces of land wanted to let water flow through the other man’s piece of land to reach his second piece of land. But the owner of that land refused and said: You cannot let the water flow through my land. The matter was referred to the caliph ‘Umar ibn Al-Khattab (may Allah be pleased with him), and he ruled that the water should be allowed to flow through that man’s land whether he liked it or not. He said: I shall surely let it flow, even if it flows across your stomach – or across your back – because this neighbour who refused to let the water flow through his land only wanted to harm him thereby, otherwise there is something that serves his interests, meaning that he would be able to benefit by planting trees or crops due to this water flowing through his land, which is something that serves the interests of both parties." (Liqa’ Al-Bab Al-Maftuh  18/122)
It may be understood from the verses which we have quoted that the Quran – on its own – contains detailed explanations for everything that people need. The scholars answered this in two ways:

The Quran indicates that the Sunnah, scholarly consensus (Ijma‘), and analogy (Qiyas) constitute sound proof. Therefore it may be stated correctly that whatever is established on the basis of these proofs is referred to in the Quran.
The Quran itself includes an explanation of that issue in one way or another, even if that is by virtue of the fact that things are to be deemed permissible in some cases.

Even though, in this discussion, we are not trying to prove that all rulings are mentioned in the Quran – rather our aim is to prove that Shari`ah , with its sources that are recognised as such, can produce rulings on all issues – it is worth mentioning what was confirmed by Ar-Razi (may Allah have mercy on him) concerning the second argument, after he noted that the first argument is the view of the majority of jurists.
Ar-Razi (may Allah have mercy on him) said: 
“With regard to his view that this Book does not contain all the rulings having to do with fundamental and minor issues, we say: As for the fundamental issues, they are all to be found in the Quran, because these fundamentals are mentioned in it in the most eloquent manner.
As for the various views of the Madhhabs and the details of those different views, there is no need for it.
As for the detailed discussion of the minor issues, we say: The scholars have two views regarding that.
1- The first view: they say that the Quran indicates that Ijma‘ (scholarly consensus), Ahad reports and Qiyas (analogy) are to be regarded as proof in Shari`ah , so whatever is proven on the basis of these three proofs is, in reality, proven by the Quran.
Al-Wahidi (may Allah have mercy on him) gave three examples of that:

The first example: It was narrated that Ibn Mas‘ud (may Allah be pleased with him) used to say: Why should I not curse those whom Allah cursed in His Book, meaning the woman who does tattoos and the one who asks for tattoos to be done, and the woman who does hair extensions and the woman who asks for hair extensions to be done. And it was narrated that a woman read the entire Quran, then she came to him and said: O Ibn Umm ‘Abd, yesterday I read the Quran from cover to cover, and I did not find in it any cursing of the woman who does tattoos and the woman who asks for tattoos to be done. He (may Allah be pleased with him) said: If you had read it, you would have found it. Allah, may He be Exalted, says (interpretation of the meaning):

{And whatever the Messenger has given you - take.} [An-Nashr 59:7]
And one of the things that the Messenger of Allah brought to us is that he said: “May Allah curse the woman who does tattoos and the woman who asks for tattoos to be done.”
I say: It is possible to find the ruling on this issue in the Book of Allah in a verse that is clearer than that, because Allah, may He be Exalted, says in Surat An-Nisa’:
{and they [actually] call upon none but a rebellious Satan, Whom Allah has cursed.} [An-Nisa’ 4:117-118]
Thus Allah cursed him, then He listed some of his abhorrent deeds, among which He mentioned his saying:
{“and I will command them so they will change the creation of Allah”.} [An-Nisa’ 4:119]
The apparent meaning of this verse indicates that changing the creation of Allah will lead to being cursed.

The second example: it was narrated that Ash-Shafi‘i (may Allah have mercy on him) was sitting in Al-Masjid Al-Haram, and he said: You will not ask me about anything but I will give you an answer to it from the Book of Allah, may He be Exalted. So a man said: What do you say about a pilgrim in Ihram who kills a wasp?

He said: He does not have to do anything [as expiation] The man said: Where is that in the Book of Allah? He said: Allah, may He be Exalted, says (interpretation of the meaning):
{And whatever the Messenger has given you - take.} [Al-Nashr 59:7]
Then he mentioned a report, with an Isnad [chain of narration] going back to the Prophet (blessings and peace of Allah be upon him), that he said: “You must adhere to my Sunnah and the way of the Rightly-Guided Caliphs who come after me.” Then he mentioned, with a chain of narration going back to ‘Umar (may Allah be pleased with him) that he said: The pilgrim in Ihram may kill a wasp.
Al-Wahidi (may Allah have mercy on him) said: Thus he gave an answer quoting from the Book of Allah and deriving this ruling by going through three levels of narration.
I say: There is another way of proving it that is clearer, which is that in principle, the wealth of Muslims is protected. Allah, may He be Exalted, says (interpretation of the meaning):
{It will have [the consequence of] what [good] it has gained, and it will bear [the consequence of] what [evil] it has earned.} [Al-Baqarah 2:286]
{and [He will] not ask you for your properties} [Muhammad 47:36]
{do not consume one another's wealth unjustly but only [in lawful] business by mutual consent.} [An-Nisa’ 4:29]
Thus Allah forbids consuming people’s wealth except through trade. So when there is no trade, that means that it remains prohibited [to consume people’s wealth]. These general rulings dictate that there should be no penalty on the pilgrim who kills a wasp at all, and that is because adhering to the general meaning of these principles dictates that this should be the ruling.

The third example: Al-Wahidi (may Allah have mercy on him) said: It was narrated in the Hadith about the hired labourer who committed Zina that his father said to the Prophet (blessings and peace of Allah be upon him): Judge between us in accordance with the Book of Allah.

So he (blessings and peace of Allah be upon him) said: “By the One in Whose hand is my soul, I shall surely judge between you in accordance with the Book of Allah.” Then he ruled that the hired worker should be flogged and banished, and that the woman should be stoned if she admitted guilt.
Al-Wahidi (may Allah have mercy on him) said: Flogging and banishment are not mentioned in the text of the Quran. This indicates that whatever ruling was given by the Prophet (blessings and peace of Allah be upon him) is essentially the same as what is in the Book of Allah.
I say: This example is correct, because Allah, may He be Exalted, says (interpretation of the meaning):
{And We revealed to you the message that you may make clear to the people what was sent down to them.} [An-Nahl 16:44]
Everything that the Messenger (blessings and peace of Allah be upon him) explained and made clear is included in the meaning of this verse.
From these examples, it is proven that as the Quran indicates that ijma‘ (scholarly consensus) constitutes proof, and that the Ahad report constitutes proof, and that Qiyas (analogy) constitutes proof, every ruling that is established in one of these three ways is in fact proven by the Quran. It is in this way that we may understand the words of Allah:
{We have neglected nothing in the Book.} [Al-An‘am 6:38]
This is the way to understand this verse, and this way of understanding it is supported by the majority of jurists…
2- The second view with regard to the meaning of this verse is that of those who say that the Quran alone is sufficient and all rulings may be found in it.
The way to explain this is by noting that in principle everyone is free of obligations, and for any obligation there should be separate proof. Mentioning in specific texts the categories in which there is no obligation is impossible, because the categories in which there is no obligation are unlimited, and mentioning in specific texts that which is unlimited is not possible. Rather mentioning in specific texts is only possible in the case of that which is finite.
For example, there are a thousand obligations that Allah has enjoined on people; He mentioned them in the Quran, and He instructed Muhammad (blessings and peace of Allah be upon him) to convey that thousand to people. Then after that, He said:
{We have neglected nothing in the Book.} [Al-An‘am 6:38]
Thus what it means is that there is no other obligation that Allah has enjoined upon us after that thousand. Then He confirmed that in the verses:
{This day I have perfected for you your religion.} [Al-Ma’idah 5:3]
{nor [is there] anything fresh or dry, but [it] is written in a Clear Record.} [Al-An‘am 6:59]
This is the explanation of the view of these people. Further discussion of this matter is to be found in the books of Usul Al-fiqh (the fundamentals of jurisprudence). And Allah knows best." (Tafsir Ar-Razi  12/527).
Note:
The correct view regarding the verse in which Allah, may He be Exalted, says: {We have neglected nothing in the Book.} [Al-An‘am 6:38] is that what is meant by the Book here is Al-Lawh Al-Mahfuz, in which Allah, may He be Exalted, wrote the decrees of His creation. This is what is narrated from ‘Abdullah ibn ‘Abbas (may Allah be pleased with him) in his commentary on this verse.
But a better verse to quote as evidence in this context is the verse in which Allah, may He be Exalted, says:
{And We have sent down to you the Book as clarification for all things.} [An-Nahl 16:89]
See: Tafsir Ibn Jarir (9/234); Tafsir Ibn Kathir (3/253); As-Sa‘di (p. 255).
Fiqh of contemporary issues
If a novel issue arises of which there is no clear mention in the Book of Allah, may He be Exalted, or in the Sunnah of His Messenger (blessings and peace of Allah be upon him) – as in the case of some medical and economic issues, for example, such as artificial insemination, genetic engineering, and dealing in crypto currencies, for example – then the scholars study and strive to find a ruling on it, by means of analogy and deriving rulings on that basis, or by applying the general guidelines of Shari`ah, taking into consideration the objectives of Shari`ah .
No matter what the issue is, it is possible for these scholars to work out the Shar`i ruling, even by referring to some of the basic principles, because there are things which are either in principle permitted or forbidden, if there is no evidence to suggest otherwise, so it is not possible that there could be any issue for which there is no ruling in Islamic Shari`ah.
For more information, please see: Tafsir Adwa’ Al-Bayan by Ash-Shinqiti, on the verse {Indeed, this Quran guides to that which is most suitable.} [Al-Isra’ 17:9]
In conclusion, the Islamic system of law (Shari`ah) provides all that people need of rulings regarding all their affairs, because it is the final system of law, the perfect and complete religion, as Allah, may He be Exalted, says (interpretation of the meaning):
{This day I have perfected for you your religion and completed My favour upon you and have approved for you Islam as religion.} [Al-Ma’idah 5:3]
And Allah knows best.