Sayyiduna Abu Rafi' (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever washes a dead person and conceals his faults, forty major sins will be forgiven for him. And whoever digs a grave for his brother until he covers him in it, it is as if he has housed him in a dwelling until the Day of Resurrection."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 925