Sahih Muslim Book - 45, Hadith - 6578

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ ، حَدَّثَنَا لَيْثٌ ، عَنْ عُقَيْلٍ ، عَنِ الزُّهْرِيِّ ، عَنْ سَالِمٍ ، عَنْ أَبِيهِ ، أَنَّ رَسُولَ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ، قَالَ: الْمُسْلِمُ أَخُو الْمُسْلِمِ ، لاَ يَظْلِمُهُ وَلاَ يُسْلِمُهُ ، مَنْ كَانَ فِي حَاجَةِ أَخِيهِ كَانَ اللَّهُ فِي حَاجَتِهِ ، وَمَنْ فَرَّجَ عَنْ مُسْلِمٍ كُرْبَةً ، فَرَّجَ اللَّهُ عَنْهُ بِهَا كُرْبَةً مِنْ كُرَبِ يَوْمِ الْقِيَامَةِ ، وَمَنْ سَتَرَ مُسْلِمًا سَتَرَهُ اللَّهُ يَوْمَ الْقِيَامَةِ.

It was narrated from Salim, from his father, that the Messenger of Allah (s.a.w) said: "The Muslim is the brother of his fellow Muslim; he does not wrong him or let him down. The one who meets the needs of his brother, Allah will meet his needs. Whoever relieves a Muslim of distress, Allah will relieve his of distress on the Day of Resurrection. Whoever conceals (the faults of) a Muslim, Allah will conceal him on the Day of Resurrection."