Sahih Muslim 4490
صحيح مسلم#4490SahihAbd al-Rahman b. Abu Bakra reported:My father dictated (and I wrote for him) to Ubaidullah b. Abu Bakra while he was the judge of Sijistan: Do not judge between two persons when you are angry, for I have heard Allah's Messenger (ﷺ) as saying: None of you should judge between two persons when he is angry
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 30:21