Sahih Muslim
The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wal-Adab)
Book Number: 032 / Hadith Number: 6266
Abu Huraira reported Allah's Apostle (may peace be upon him) as saying: The servant (whose fault) Allah conceals in this world, Allah would also conceal (his faults) on the Day of Resurrection.