Jami` at-Tirmidhi 3188

Narrated Abu Hurairah, may Allah be pleased with him:"The Messenger of Allah (ﷺ) said to his uncle: 'Say La Ilaha Illallah and I may bear witness with that, on your behalf, on the Day of Judgement.' So he said: 'If it weren't that the Quraish would insult me (saying): "He only said it out of fright" then I would delight your eyes.' Then Allah the Mighty and Sublime revealed: Verily, you guide not whom you like, but Allah guides whom He wills (28:)