Mukhtasar Sahih Bukhari — Hadith 1115

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, so he should neither oppress him nor disgrace him. Whoever is engaged in fulfilling the need of his brother, Allah Almighty fulfills his need, and whoever removes a calamity from a Muslim, Allah Almighty will remove one of his calamities from the calamities of the Day of Resurrection. And whoever conceals the fault of a Muslim, Allah Almighty will conceal his fault on the Day of Resurrection.”