Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "A Muslim is the brother of a Muslim; he does not oppress him nor does he hand him over to anyone. Whoever fulfills the need of his brother, Allah Almighty will fulfill his need; whoever removes a difficulty of his Muslim brother, Allah Almighty will remove one of his difficulties on the Day of Resurrection; and whoever conceals the faults of his Muslim brother, Allah Almighty will conceal his faults on the Day of Resurrection."