Ṣaḥīḥ Muslim 134

The full narration

It is narrated on the authority of Abu Huraira that the Messenger of Allah said to his uncle at the time of his death:Make a profession of it that there is no god but Allah and I will bear testimony (of your being a Muslim) on the Day of judgment. But he (Abu Talib) refused to do so. Then Allah revealed this verse: " Verily thou canst not guide to the right path whom thou lovest. And it is Allah Who guideth whom He will and He knoweth best who are the guided" (xxviii)