Full Sharh — Al-Adab Al-Mufrad 495
حَدَّثَنَا مُوسَى، قَالَ: حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ عَبْدِ الْمَلِكِ بْنِ عُمَيْرٍ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ سَعِيدٍ، عَنْ أَبِيهِ قَالَ: كُنْتُ مَعَ سَلْمَانَ، وَعَادَ مَرِيضًا فِي كِنْدَةَ، فَلَمَّا دَخَلَ عَلَيْهِ قَالَ: أَبْشِرْ، فَإِنَّ مَرَضَ الْمُؤْمِنِ يَجْعَلُهُ اللَّهُ لَهُ كَفَّارَةً وَمُسْتَعْتَبًا، وَإِنَّ مَرَضَ الْفَاجِرِ كَالْبَعِيرِ عَقَلَهُ أَهْلُهُ ثُمَّ أَرْسَلُوهُ، فَلاَ يَدْرِي لِمَ عُقِلَ وَلِمَ أُرْسِلَ.
English Translation
'Abdu'r-Rahman ibn Sa'id reported that his father said, "I waswith Salman when he visited a sick person in Kinda. When he went in, he said, 'Good news! Allah makes the illness of the believer an expiation for him and a restoration, whereas the illness of the corrupt person is like a camel whose people hobble it and the let it go. It does not know why it was hobbled or released.'"
Source
Al-Adab Al-Mufrad(الأدب المفرد)
Visiting the Ill
Hadith Number
495