Cover a fault, Allah will cover yours
مَنْ سَتَرَ مُسْلِمًا سَتَرَهُ اللَّهُ فِي الدُّنْيَا وَالْآخِرَةِ
Man satara musliman satarahu-llahu fi-d-dunya wa-l-akhirah.
"Whoever covers [the fault of] a Muslim, Allah will cover him in this world and the next."
Narrated by Ibn Umar. Sahih al-Bukhari 2442, Sahih Muslim 2580
A short reflection
Gossip is easy. The hadith's promise runs in the opposite direction — conceal, and you'll be concealed when it matters.