عَنْ أَبِي مُوسَى قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَطْعِمُوا الْجَائِعَ وَعُودُوا الْمَرِيض وفكوا العاني» . رَوَاهُ البُخَارِيّ

He and Abu Sa'id reported the Prophet as saying, “No Muslim is afflicted by difficulty, continuous pain, anxiety, grief, injury, or care, or even by a thorn with which he is pierced, without God thereby making an atonement for his sins.”(Bukhari and Muslim.)