Hazrat ‘Ali (radhiyallahu ‘anhu) narrates:

When the verse “And warn your close relatives” was revealed, Rasulullah (sallallahu ‘alaihi wasallam) instructed me to bring a saa’ (approximately 3.2kg) of grain, the shoulder of a goat and a bowl of milk. He then requested me to summon all the children of Muttalib.I did as instructed and approximately forty people responded. Among them were his uncles; Abu Taalib, Hamzah, ‘Abbaas and Abu Lahab.