﴿ يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ لَا تَسْـَٔلُوا۟ عَنْ أَشْيَآءَ إِن تُبْدَ لَكُمْ تَسُؤْكُمْ وَإِن تَسْـَٔلُوا۟ عَنْهَا حِينَ يُنَزَّلُ ٱلْقُرْءَانُ تُبْدَ لَكُمْ عَفَا ٱللَّهُ عَنْهَا ۗ وَٱللَّهُ غَفُورٌ حَلِيمٌۭ ﴾

“O YOU who have attained to faith! Do not ask about matters which, if they were to be made manifest to you [in terms of law], might cause you hardship; for, if you should ask about them while the Qur'an is being revealed, they might [indeed] be made manifest to you [as laws]. God has absolved [you from any obligation] in this respect: for God is much-forgiving, forbearing.”

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).