Jami` at-Tirmidhi, Hadith 969 ⓘ
Thuwair [and he is Ibn Abi Fakhitah] narrated that : His father said: "Ali took me by the hand and said: 'Come with us to pay a visit to Al-Hasan.' So we found that Abu Musa was with him.' Ali - peace be upon him - said: 'O Abu Musa! Did you come to visit (the sick) or merely (stop by to) visit?' He said: 'No, to visit (the sick).' So Ali said: 'I heard the Messenger of Allah saying: "No Muslim visits (the sick) Muslims in the morning, except that sevety-thousand angels, sent Salat upon him until the evening, and he does not visit at night except that seventy thousand angels sent Salat upon him until the morning, and there will be a garden for him in Paradise."
حَدَّثَنَا أَحْمَدُ بْنُ مَنِيعٍ، حَدَّثَنَا الْحُسَيْنُ بْنُ مُحَمَّدٍ، حَدَّثَنَا إِسْرَائِيلُ، عَنْ ثُوَيْرٍ، هُوَ ابْنُ أَبِي فَاخِتَةَ عَنْ أَبِيهِ، قَالَ أَخَذَ عَلِيٌّ بِيَدِي قَالَ انْطَلِقْ بِنَا إِلَى الْحَسَنِ نَعُودُهُ . فَوَجَدْنَا عِنْدَهُ أَبَا مُوسَى فَقَالَ عَلِيٌّ عَلَيْهِ السَّلاَمُ أَعَائِدًا جِئْتَ يَا أَبَا مُوسَى أَمْ زَائِرًا فَقَالَ لاَ بَلْ عَائِدًا . فَقَالَ عَلِيٌّ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " مَا مِنْ مُسْلِمٍ يَعُودُ مُسْلِمًا غُدْوَةً إِلاَّ صَلَّى عَلَيْهِ سَبْعُونَ أَلْفَ مَلَكٍ حَتَّى يُمْسِيَ وَإِنْ عَادَهُ عَشِيَّةً إِلاَّ صَلَّى عَلَيْهِ سَبْعُونَ أَلْفَ مَلَكٍ حَتَّى يُصْبِحَ وَكَانَ لَهُ خَرِيفٌ فِي الْجَنَّةِ " . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ وَقَدْ رُوِيَ عَنْ عَلِيٍّ هَذَا الْحَدِيثُ مِنْ غَيْرِ وَجْهٍ مِنْهُمْ مَنْ وَقَفَهُ وَلَمْ يَرْفَعْهُ . وَأَبُو فَاخِتَةَ اسْمُهُ سَعِيدُ بْنُ عِلاَقَةَ .
also referenced under: Book 10, Hadith 5 (In-Book) & Volume 2, Book 8, Hadith 969 (DarusSalam)