(Prove orphans…) [4:6]. This was revealed about Thabit ibn Rifa‘ah and his uncle. Rifa‘ah died when his son Thabit was very young. The uncle of Thabit went to the Messenger of Allah, Allah bless him and give him peace, and said: “The son of my brother is an orphan under my care, what is lawful for me from his wealth? And when should I give him back his wealth?” And so Allah, exalted is He, revealed this verse.
Asbab Al-Nuzul by Al-Wahidi , trans. Mokrane Guezzou