(Not equal are the bad things and the good things, even though they may please you) O human,
كَثْرَةُ الْخَبِيثِ
(the abundance of bad.) This Ayah means, the little permissible is better than the abundant evil.
فَاتَّقُواْ اللَّهَ يأُوْلِى الأَلْبَـبِ
(have Taqwa of Allah, O men of understanding...) who have sound minds, avoid and abandon the impermissible, and let the permissible be sufficient for you,
لَعَلَّكُمْ تُفْلِحُونَ
(in order that you may be successful.) in this life and the Hereafter. " So have Taqwa of Allah, O men of understanding in order that you may be successful.) (101. O you who believe! Ask not about things which, if made plain to you, may cause you trouble. But if you ask about them while the Qur'an is being revealed, they will be made plain to you. Allah has forgiven that, and Allah is Oft-Forgiving, Most Forbearing.) (102. Before you, a community asked such questions, then on that account they became disbelievers.) Allah says to His Messenger ,
These verses warn people who keep investigating unnecessarily into Divine injunctions. So fond and bent are they in this exercise that they would go to the outer limit of asking questions even about in-junctions which have not been prescribed at all and for which there is really no genuine need that they be asked. In this verse, such people have been instructed not to ask questions lest they are subjected to some trial, or they have to face disgrace as a result of the disclosure of their secrets.
The Background of the Revelation
As narrated in Sahib Muslim, the background or the cause of the revelation of these verses is as follows. When the verse concerning the obligation of Hajj was revealed, Sayyidna Al-Aqra` ibn Habis ؓ asked: ` Have we been obligated with Hajj every year?' The Holy Prophet ﷺ did not answer that question. He asked again. The Holy Prophet still remained silent. When he asked a third time, the Holy Prophet ﷺ reprimanded him by saying: If, in answer to your question, I had said, ` Yes, the Hajj is obligatory every year' - so it would have become, and you would have been unable to do it. After that, he added: Things about which I give you no command, leave them as they are. Do not ask questions by digging and prying into them. Communities before you have been damned eternally through this very proliferation of questioning because they, questions after questions about what Allah and His Messenger did not make obligatory on them, and in consequence of their unnecessary enquiry, these optional things were made obligatory - and then, they got involved in the unfortunate practice of disobeying these. Your estab-lished routine should be: Do what I order you to do, with the best of your ability, and leave what I order you not to do (that is, do not dig and pry into things about which no injunctions are given).
It has been recorded in the traditions that when the order regarding Hajj was received, the Prophet Muhammad said in a sermon ‘O, people! Hajj has been made compulsory for you.’ On hearing this, a person from the Banu Asad tribe got up and asked: ‘O, Prophet of God! Is it for every year?’ The Prophet Muhammad was very angry and said, ‘By the Lord in whose hands my life is! Had I said “‘Yes”, it would have become compulsory for every year, and having become compulsory for every year, you would not have been able to perform it every year and thus committed denial of truth.’ So, leave out whatever I leave out. When I order anything to be done, do it, and when I prohibit you from doing anything, don’t do it.’ (Tafsir ibn Kathir).
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.