Musnad Ahmad 2977

It was narrated that Ibn ‘Abbas (رضي الله عنه) said: When the verse "And come not near to the orphan's property except to improve it” [al-An'am 6:52, al-Isra' 17:34] was revealed, they put orphans' wealth aside, until the food started to go off and meat began to go rotten, Mention of that was made to the Prophet (ﷺ), then the verse “and if you mix your affairs with theirs, then they are your brothers. And Allah knows him who means mischief (e.g. to swallow their property) from him who means good (e.g. to save their property)" [al-Baqarah 2:220] was revealed. He said: Then they mixed their affairs with theirs.