The wisdom behind singling out the month of Ramadan for worship
Question

Why did the Messenger (blessings and peace of Allah be upon him) single out the month of Ramadan in particular for worship?
Praise be to Allah.Firstly:
Allah, may He be glorified and exalted, is the All-Knowing, Most Wise. The believer may know the wisdom behind the laws that Allah prescribes, or he may not know, in which case he should say as the angels said (interpretation of the meaning): “Exalted are You; we have no knowledge except what You have taught us. Indeed, it is You who is the Knowing, the Wise” [al-Baqarah 2:32].
Allah, may He be exalted, has given precedence to some times over others and some people over others, high ranks conferred by Him. Allah singles out for His mercy whomever He wills.
We do not know for certain the wisdom behind the singling out of the month of Ramadan as a time for worship.
Allah, may He be glorified and exalted, is the Creator and Sovereign of all. He created time and gave greater honour to some times over others. He created places and gave greater honour to some places over others. He created people and chose some of them over others. This is a sign of His perfect greatness of which no one can understand the nature, and is a sign of His perfect sovereignty, which people cannot comprehend. Allah, may He be exalted, says (interpretation of the meaning):
“They have not appraised Allah with true appraisal. Indeed, Allah is Powerful and Exalted in Might.
Allah chooses from the angels messengers and from the people. Indeed, Allah is Hearing and Seeing.
He knows what is [presently] before them and what will be after them. And to Allah will be returned [all] matters”
[al-Hajj 22:74-76].
This is a sign of His perfect will, which encompasses all things, and of the greatness of His Lordship and His power and authority, may He be glorified. Allah, may He be exalted, says (interpretation of the meaning):
“Difficult for those who associate others with Allah is that to which you invite them. Allah chooses for Himself whom He wills and guides to Himself whoever turns back [to Him]”
[ash-Shoora 42:13]
“And your Lord creates what He wills and chooses; not for them was the choice. Exalted is Allah and high above what they associate with Him”
[al-Qasas 28:68].
Ibn al-Qayyim (may Allah have mercy on him) said:
That is, this choice is not up to them; rather it is up to the Creator alone. Just as He is the only one Who creates, He is the only one Who chooses from His creation. No one has the power to create or choose except Him, for He, may He be glorified, knows best where His choice should fall and what pleases Him, what is fit to be chosen and what is not fit for that. No one else has any share in that whatsoever.
Then he said:
If you reflect upon creation and how people are, you will realize that this divine choice and singling out (for honour) is indicative of the Lordship and oneness of Allah, may He be exalted, and the perfect nature of His wisdom, knowledge and might, and that He is Allah, besides Whom there is no other god, so he has no partner who can create as He creates, choose as He chooses, and control as He controls.
This choosing and controlling of creation and singling some out for honour, which is noticeable in this universe, is one of the greatest signs of His Lordship, and is one of the greatest testimonies to His Oneness, His perfect attributes and the truthfulness of His Messengers. Hence we will point out some examples of that, which will be sufficient to prove the point.
Allah created the seven heavens, then chose the highest of them and made it the abode of the angels who are closest to Him, as He chose that heaven to be closest to His Footstool (Kursiy) and His Throne (‘Arsh); He caused to dwell therein whomever He willed of His creation. Hence it is superior to all the other heavens, and even if there were nothing except it being close to Him, may He be blessed and exalted, (that would be sufficient to prove its superiority).
This singling out for honour, even though the nature of the heavens is all the same, is one of the clearest proofs of the perfect power and wisdom of Allah, and that He creates what He wills and chooses.
Allah, may He be glorified, gave precedence to Jannat al-Firdaws over all the other gardens of Paradise, and singled it out by making His Throne its roof. According to one report, “Allah, may He be glorified, planted it with His own Hand and chose it for the best of His creation.”
Allah chose the elite of the angels from among all of them, such as Jibreel, Mikaa’eel and Israafeel. The Prophet (blessings and peace of Allah be upon him) used to say: “O Allah, Lord of Jibra’eel, Mika’eel and Israfeel, Originator of the heavens and the earth, Knower of the unseen and the seen, You judge between Your slaves concerning that wherein they differ. Guide me concerning that wherein they differ of the truth by Your leave, for You guide whomsoever You will to a straight path.”
These three angels are mentioned because they are the crème de la crème of the angels and are the closest to Allah. How many angels there are besides them in the heavens, but he only named these three. Jibreel is the bringer of revelation, which gives life to hearts and souls; Mikaa’eel is the bringer of rain, which gives life to the earth, animals and plants; and Israafeel is the keeper of the Trumpet – when he blows it, the sound will, by Allah’s leave, reach all the dead and bring them forth from their graves….
End quote from Zaad al-Ma‘aad (1/42 ff).
Then he (may Allah have mercy on him) said:
Allah gave precedence to some days and months over others. The best of days with Allah is the Day of Sacrifice, which is the greatest day of the Hajj.
He gave precedence to the month of Ramadan over all other months, and give precedence to the last ten nights thereof over all other nights, and He made Laylat al-Qadr better than a thousand months.
The point is that Allah, may He be glorified and exalted, has chosen from every category of creation the best; He has singled it out for Himself and chosen it to be pleased with, to the exclusion of others. For He, may He be exalted, is good; He does not love anything except that which is good, and He does not accept any deeds or words or charity except those that are good. What is good of everything is what He chooses, may He be exalted.
End quote from Zaad al-Ma‘aad (1/57, 54, 64).
Secondly:
With regard to the Messenger of Allah (blessings and peace of Allah be upon him) singling out the month of Ramadan for worship and fasting:
If what is meant is his singling it out for that purpose after his Prophethood began, he only did that on the basis of what Allah, may He be exalted, revealed to him, and this is what Allah chose for His slaves, and commanded them to fast that month and worship Him during it more than in other months. This is what has been explained in the first part of our answer.
But if what is meant is asking about the Prophet’s retreat and worship of his Lord in the Cave of Hira’ before revelation came down to him and before Allah honoured him with Prophethood, we do not know anything about the details of that or why he (blessings and peace of Allah be upon him) chose that. Knowing about that or otherwise does not undermine any issues of religion, because the religion and its teachings are what the Prophet (blessings and peace of Allah be upon him) brought after his Prophethood began. As for what he did before Prophethood, we are not enjoined to follow him (blessings and peace of Allah be upon him) in any of that.
Some scholars have stated that it may be that that was a remnant of the religion of Ibraaheem (peace be upon him) that reached him as it reached other monotheists (hunafaa’, sing. haneef), who used to worship Allah alone according to the way of Ibraaheem (peace be upon him) before Allah revealed His way to His Prophet.
Al-‘Allaamah at-Taahir ibn ‘Aashoor (may Allah have mercy on him) said: The month of Ramadan was chosen out of all months, because it was honoured with the sending down of the Qur’an in that month. Because the sending down of the Qur’an was intended to purify and guide the ummah, and it contained teachings to purify souls and bring people closer to an angelic nature, it was appropriate that it should be sent down in Ramadan.
I think it most likely that the Prophet (blessings and peace of Allah be upon him) used to fast during the days of his retreat in the Cave of Hira’ before the revelation came down to him, on the basis of inspiration from Allah, may He be exalted, and following some of the surviving teachings of the way of monotheism (haneefiyyah). When the revelation came down to him in the month of Ramadan, Allah enjoined the Muslim ummah to fast in that month.
End quote from at-Tahreer wa’t-Tanweer (2/173).
And Allah knows best.