(O ye who believe! Ask not of things which, if they were made unto you, would trouble you…) [5:101]. 'Amr ibn 'Amr al-Muzakki informed us> Muhammad ibn Makki> Muhammad ibn Yusuf> Muhammad ibn Isma'il Bukhari> al-Fadl ibn Sahl> Abu'l-Nadr> Abu Khaythamah> Abu Juwayriyyah> Ibn 'Abbas who said: “Some people used to put questions to the Prophet, Allah bless him and give him peace, to mock him. One would ask him: 'Who is my father?' and another who has lost his camel: 'Where is my camel?' And so Allah, exalted is He, revealed about them this verse (O ye who believe! Ask not of things which, if they were made unto you, would trouble you) up to the end of the verse”. Abu Sa'id al-Nasruyiyy informed us> Abu Bakr al-Qati'i> 'Abd Allah ibn Ahmad ibn Hanbal> Ahmad ibn Hanbal> Mansur ibn Wardan al-Asdi> 'Ali ibn 'Abd al-A'la> his father> Abu'l-Bukhturi> 'Ali ibn Abi Talib, may Allah be well pleased with him, who said: “When the verse (And pilgrimage to the House is a duty unto Allah for mankind) [3:97], people asked: 'O Messenger of Allah, is it every year?' He did not answer but they asked him again: 'Is it every year?' He kept silent. When they asked him the fourth time he said: 'No! But if I had said 'yes!' it would have been incumbent upon you to go to pilgrimage every year'. Following this, Allah, exalted is He, revealed (O ye who believe! Ask not of things which, if they were made unto you, would trouble you)”.
Asbab Al-Nuzul by Al-Wahidi , trans. Mokrane Guezzou