سنن النسائي

It was narrated from Sa'eed bin Al-Musayyab that his father said: "When Abu Talib was dying, the Prophet (ﷺ) came to him and found Abu Jahl and 'Abdullah bin Abi Umayyah with him. He said: 'O uncle, say La ilaha illallah(there is none worthy of worship except Allah), a word with which I will defend you before Allah.' Abu Jahl and 'Abdullah bin Abi Umayyah said: 'O Abu Talib, are you turning away from the religion of 'Abdul-Muttalib.' Then the Prophet (ﷺ) said: 'I will keep on asking for Allah's forgiveness for you unless I am forbidden to do so.' Then the following was revealed: It is not (proper) for the Prophet (ﷺ) and those who believe to ask Allah's forgiveness for the idolaters. And the following was revealed: Verily, you (O Muhammad) guide not whom you like."