The principles of tafseer (Quranic exegesis)
Question

My question is that I read the hadith somewhere which says that someone who interprets the Quran in personal views has erred. Can u please elaborate on that? Sometimes, if one feels connected to a certain verse at a certain point in time- is that wrong provided that the verse may have another intended message. Also, can u please tell me how did the main sources of tafseer come then, how did the first scholars of tafseer know what a certain verse means. I read that its called tafsir bir riwaya, that is based on Quran as a source of more information about that verse too. How is the classical tafseer verified then. Also, can u give me an example of this kind of relation? What is an isnad? How do we know if something is an innovation. What are the labels that show us that a tradition is authentic.
Praise be to Allah.Firstly:
We should understand that there are principles and guidelines for interpreting the Quran, which must be properly understood by the one who engages in tafseer (exegesis) of the word of Allah, may He be blessed and exalted. The scholars have written about the guidelines and principles of tafseer, and have explained the difference between tafseer on the basis of reports and tafseer on the basis of one’s own understanding; they have explained when it is acceptable for a person to speak on the basis of his own understanding; and have differentiated between good understanding and poor understanding, especially with regard to what is mentioned in the question about a person coming up with his own understanding of a verse and understanding it on the basis of what he thinks to be right. Such personal understanding and thoughts should be measured against what the scholars said about the interpretation of this verse, and so on.
If the one who has his own personal understanding and thoughts is a seeker of knowledge, and is able to check what the commentators and scholars said, then he may find out for himself what was narrated concerning the meaning of the verse, and the views of respected commentators about the meaning and how they explained the meaning. Then if what he came up with about the meaning of the verse is in accordance with some of these views of respected scholars, then all well and good.
But if it is not in accordance with these scholarly views, then he must correct his understanding of the verse by checking it against the views of the scholars. However, he may not find the meaning that he came up with mentioned in the books (of tafseer) that he checks, or it may not be stated exactly as he had in mind, but the view that he came up with may be in harmony with the wording and context of the verse, and with the way that meanings are expressed in Arabic, and may indicate that meaning or point to it in one way or another, and in a way of expression that is regarded as possible by the scholars.
This requires further examination and study of the views of the scholars (concerning the verse), because the understanding that he developed could be implied in the wording of some scholars in their commentary on the verse.
He may, if possible, discuss his idea (about the meaning of the verse) with some scholars who have knowledge of the Book of Allah and the meaning of its verses.
You can refer to the following books

Sharh Muqaddimah fi Usool at-Tafseer, by Shaykh Dr. Musaa‘id at-Tayyaar
At-Tahreer fi Usool at-Tafseer by Shaykh Dr. Musaa‘id at-Tayyaar

to learn about these issues that you need to learn and understand before you venture into the interpretation of the word of Allah, may He be exalted.
Secondly:
The scholars have stated that the Quran may be interpreted:

By the Quran
By the Sunnah
By the words of the early generations (salaf)
By the rules of the Arabic language
By referring to some of the reports of the People of the Book, and the reasons for revelation (asbaab an-nuzool), in order to understand the meaning of a particular verse.

For each of these guidelines there is shar‘i evidence, within the framework of which tafseer is to be done. The Quran is the most appropriate means of understanding the Quran, because it is the word of Allah, may He be exalted. The Messenger is the one who explains the words of Allah, for that is his role. The Quran was revealed in the language of the Arabs, so it [the Arabic language and its rules of grammar and expression] is one of the basic means of understanding the Quran. The early generations were the closest of people to the language and the most knowledgeable of what meaning the Messenger intended when he spoke, for they were witnesses to the revelation and were aware of the circumstances of and reasons for revelation; they are also people who were proven to be good and righteous, so their interpretation takes precedence over that of others.
If you want detailed proof, we advise you to refer to the book al-Istidlaal ‘ala al-Ma‘aani fi Tafseer at-Tabari, by Dr. Naayif az-Zahraani, in which he mentions the evidence for all of this.
Thirdly:
The scholars have ways of differentiating between what is sound (saheeh) and what is weak (da‘eef), namely mustalah al-hadith (the science of hadith). By means of this science, a scholar is able to differentiate between what is sound and what is not, and to differentiate between what is acceptable and what is not acceptable of reports.
They have a particular way of dealing with the reports of tafseer; you can find details of that in the books mentioned above.
Fourthly:
With regard to the hadith “Whoever gives his personal view about the Book of Allah and it turns out to be correct is still mistaken,” that is, because he spoke about something of which he has no certain knowledge, and he approached the matter in a way other than what is enjoined. So even if he was correct in what he said about the meaning when he gave his view on the matter, he still erred, because he did not have the right approach to the matter. He is like one who judges between people on the basis of ignorance: he will be in the Fire, even if he happened to give the right ruling, but his sin is less grave than that of one who gives a wrong ruling. And Allah knows best. This is similar to the case in which Allah calls those who accuse others of adultery (“slander”) liars, as He says (interpretation of the meaning): “And when they do not produce the witnesses, then it is they, in the sight of Allah, who are the liars” [an-Noor 24:13]. The slanderer is a liar, even if his accusation of adultery is correct in and of itself, because he spoke of something of which it is not permissible to speak, even if he spoke on the basis of what he knows, because he has spoken of something of which he does not have certain knowledge. And Allah knows best.
See: Majmoo‘ al-Fatawa (13/371); Tafseer Ibn Katheer (1/11).
For more information, please see the answer to question no. 205290 .
And Allah knows best.