Hadith #12 (The Forty Hadith of Imam Nawawi)
Book: Leaving what does not concern one
Narrator(s): Abu Hurairah
Grade: Hasan

The Messenger of Allah (peace and blessings of Allah be upon him) said, “Part of the perfection of one’s Islam is his leaving that which does not concern him.”

Source: https://parallelquran.com/hadith/forty-nawawi-12/