Rabee‘ah bin ‘Ibaad (radhiyallahu ‘anhu) says:

I once saw Rasulullah (sallallahu ‘alaihi wasallam) in the markets of ‘Ukkaaz and Zul Majaaz inviting people towards Islam saying:

يا أيها الناس قولوا لا إله إلا الله تفلحوا

O people! Say “Laa Ilaaha Illallah” and you will be successful!

While he was inviting people towards Islam, I saw a squint-eyed man walking behind him and calling out to the people, “This man has renounced the religion of his forefathers and he is a liar!” When I asked the people who this man was, they informed me that he was the uncle of Rasulullah (sallallahu ‘alaihi wasallam), Abu Lahab.