It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said to his uncle (Khawaja Abu Talib at the time of his death): "Acknowledge 'La ilaha illallah' (There is no god but Allah), so that I may testify on your behalf with it on the Day of Resurrection." He replied, "If it were not that the people of Quraysh would taunt me, saying that he recited this word out of fear, I would cool your eyes (i.e., make you happy by accepting it)." Upon this, Allah revealed this verse: "You cannot guide whom you love."