It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said:
"Whoever covers (the sin of) a Muslim, Allah will cover him (his sin) in this world and in the Hereafter." (ID)
English reference (ID): Vol. 3, Book 20, Hadith 2544 (ID)
Arabic reference (ID): Book 20, Hadith 2641 (ID)