Hazrat Abdullah bin Umar, Allah be pleased with him, narrated that the Holy Prophet, peace and blessings of Allah be upon him, said:
“A Muslim is a brother of another Muslim, so he should not oppress him, nor should he hand him over to an oppressor. Whoever fulfilled the needs of his brother, Allah will fulfill his needs; whoever brought his brother out of a discomfort, Allah will bring him out of discomfort on the Day of Resurrection and whoever screened a Muslim, Allah will screen him on the Day of Resurrection.”
(Sahih al-Bukhari, Kitab Al-Muzalim)