This verse forbids people to ask useless and unnecessary questions because some people used to put such questions to Prophet Muhammad ﷺ as were of no practical good for mundane affairs nor for spiritual up-lift.
For example, once a certain person while sitting in a gathering asked him, "Who is my real father?'' Likewise, sometimes, some people put unnecessary questions concerning legal matters so as to get these defined, whereas they had been purposely kept undefined for the good of the people. Far example, when Hajj was made obligatory by a commandment in the Qur'an a certain person heard it, and instantly asked. "Has it been made obligatory to perform Hajj every year'" Prophet ﷺ did not make any reply. The man repeated the question, but he again kept quiet. When the man put the question for the third time, he replied, "Woe to you! If I had said: 'Yes', the performance of Hajj every year would have become obligatory and people like you would have been unable to perform it and been guilty of disobedience. "
Prophet ﷺ himself forbade people to ask questions for the sake of it and to probe into things aimlessly. In a Tradition he warned, "The worst offender against the Muslims is the person who asked a question about something that had not been made unlawful but was made so because of his question." In another Tradition he said{
"Allah has prescribed some obligatory duties for you; let not these go unfulfilled, and He has made certain things unlawful, so do not go near them. He has prescribed certain limits, do not transgress them. He has been silent concerning certain things, but not because He has forgotten them; so do not try to probe into such things."
In these two Traditions a warning has been served against a very serious matter. There are certain things and commandments which have been left vague and without details. This is not because the Law-giver had forgo ten to give details or to make them specific but because He did not intend to limit these in order to leave a wide scope for the people. Therefore if a person goes on creating one issue after the other, by putting unnecessary and useless questions and thus creates limitations and specifications, he puts the people to unnecessary trouble. Likewise if he tries to deduce the details by the force of his "reasoning". and does trot rest content till .he has made the vague things specific and the indefinite definite. he in reality puts the Muslims in a very awkward position. This is because the more details we otter for the Unseen and the Next World, the more will be the chances for creating doubts about them and, likewise, the more limitations are imposed concerning the Commandments, the greater will be the chance for their violation.
Muhammad Asad Explanation:
This verse connects directly with verse {99}: "No more is the Apostle bound to do than deliver the message." Read in conjunction with the sentence, "Today have I perfected your religious law for you" (occurring in verse {3} of this surah), the above statement implies that the believers should not try to deduce "additional" laws from the injunctions clearly laid down as such by the Qur'an or by the Prophet, since this "might cause you hardship" - that is, might (as has indeed happened in the course of the centuries) impose additional burdens on the believers above and beyond anything that has been stipulated in terms of law in the Qur'an or in the authentic commandments of the Prophet. On the basis of this verse, some of the greatest Muslim scholars have concluded that Islamic Law, in its entirety, consists of no more than the clear-cut injunctions forthcoming from the self-evident (zahir) wording of the Qur'an and the Prophet's commandments, and that, consequently, it is not permissible to extend the scope of such self-evident ordinances by means of subjective methods of deduction. (A most enlightening discussion of this problem is to be found in the Introduction to Ibn Hazm's Muhalla, vol. I, 56 ff.) This, of course, does not prevent the Muslim community from evolving, whenever necessary, any amount of additional, temporal legislation in accordance with the spirit of the Qur'an and the teachings of the Prophet: but it must be clearly understood that such additional legislation cannot be regarded as forming part of Islamic Law (the shari'ah) as such.
( for, if you should ask about them while the Qur'an is being revealed, they might [indeed] be made manifest to you [as laws] ) I.e., with possibly unfortunate consequences. An illustration of this problem has been provided in the following authentic Tradition, quoted by Muslim on the authority of Abu Hurayrah. In one of his sermons, the Prophet said: "O my people! God has ordained the pilgrimage (al-hajj) for you; therefore perform it." Thereupon somebody asked, "Every year, O Apostle of God?" The Prophet remained silent; and the man repeated his question twice. Then the Prophet said: "Had I answered 'yes', it would have become incumbent on you [to perform the pilgrimage every year]: and, indeed, it would have been beyond your ability to do so. Do not ask me about matters which I leave unspoken: for, behold, there were people before you who went to their doom because they had put too many questions to their prophets and thereupon disagreed [about their teachings]. Therefore, if I command you anything, do of it as much as you are able to do; and if I forbid you anything, abstain from it." Discussing this Tradition, Ibn Hazm observes: "It circumscribes all the principles of religious law (ahkam ad-din) from the first to the last - namely: what the Prophet has left unspoken - neither ordering nor forbidding it - is allowed (mubah), that is, neither forbidden nor obligatory; whatever he ordered is obligatory (fard), and whatever he forbade is unlawful (haram); and whatever he ordered us to do is binding on us to the extent of our ability alone" (Muhalla I, 64). It should be borne in mind that the term "the Prophet" comprises, in this context, the Qur'an as well, since it was through the Prophet that the Qur'anic message was communicated to mankind.
( God has absolved [you from any obligation] in this respect: for God is much-forgiving forbearing ) I.e., by leaving certain matters unspoken, God has left them to man's discretion, thus enabling him to act in accordance with his conscience and the best interests of the community.
Many secrets are wisely hidden from us. If the future were known to us, we need not necessarily be happy. In many cases we should be miserable. If the inner meaning of some of the things we see before our eyes were disclosed to us, it might cause a lot of mischief. Allah's Message, in so far as it is necessary for shaping our conduct, is plain and open to us. But there are many things too deep for us to understand, either individually or collectively. It would be foolish to pry into them, as some people tried to do in the time of the Prophet. Where a matter is mentioned in the Qur-an, we can reverently ask for its meaning. That is not forbidden. But we should never pass the bounds of (1) our own capacity to understand, (2) the time and occasion when we ask questions, and (3) the part of the Universal Plan which it is Allah's purpose to reveal to us.
Tafsir Ibn-Kathir:
(O you who believe! Ask not about things which, if made plain to you, may cause you trouble.) This Ayah refers to good conduct that Allah is teaching His believing servants, by forbidding them from asking about useless things. Since if they get the answers they sought, they might be troublesome for them and difficult on their ears. Al-Bukhari recorded that Anas bin Malik said, "The Messenger of Allah gave a speech unlike anything I heard before.
In this speech, he said, (If you but know what I know, you will laugh little and cry a lot.) The companions of Allah's Messenger covered their faces and the sound of crying was coming out of their chests.
Anas bin Malik narrated that once, the people were questioning the Messenger of Allah until they made him angry. So he ascended the Minbar and said, (You will not ask me about anything today but I will explain it to you.) So the Companions of the Messenger of Allah feared that it was the commencement of a momentous event, and I looked to my right and left and found only people who covered their faces, crying. An argumentative man who was said to be the son of someone other than his true father asked, "O Allah's Messenger! Who is my father The Prophet said, `Your father is Hudhafah.'' `Umar stood up (when he saw anger on the Prophet's face) and said, "We accept Allah as our Lord, Islam as our religion and Muhammad as our Messenger, I seek refuge with Allah from the evil of the Fitan (trials in life and religion).''
The Messenger of Allah said, (I have never witnessed both goodness and evil like I have today. Paradise and the Fire were shown to me and I saw them before that wall.) This Hadith was recorded in the Two Sahihs from Sa`id.
(O you who believe! Ask not about things which, if made plain to you, may cause you trouble.).'' At-Tirmidhi and Ibn Majah also recorded this Hadith. The apparent wording of this Ayah indicates that we are forbidden to ask about things that if one has knowledge of, he would be sorry he had asked. Consequently, it is better to avoid such questions.
Allah's statement, (But if you ask about them while the Qur'an is being revealed, they will be made plain to you.) means, if you ask about things that you are prohibited from asking about, then when the revelation about them comes to the Messenger , they will be made plain for you,
(and Allah is Oft-Forgiving, Most Forbearing.) Do not ask about things that do not have a ruling yet, for because of your questions, a difficult ruling may be ordained. A Hadith states, (The worst criminal among the Muslims is he who asks if a matter is unlawful (or not), and it becomes unlawful because of his asking about it.) It is recorded in the Sahih that the Messenger of Allah said, (Leave me as I have left you, those before you were destroyed because of many questions and disputing with their Prophets.)
An authentic Hadith also states, (Allah, the Most Honored, has ordained some obligations, so do not ignore them; has set some limits, so do not trespass them; has prohibited some things, so do not commit them; and has left some things without rulings, out of mercy for you, not that He forgot them, so do not ask about them.)