1. Great virtues and rewards have been recorded in the Ahadith for visiting the sick.
عَن عَلِي رَضِيَ اللهُ عَنهُ قال سَمِعتُ رَسُولَ اللهِ صَلىَّ اللهُ عَلَيهِ وَ سَلَّمَ يَقُولُ مَا مِن مُسْلِمٍ يَعُودُ مُسْلِمًا غَدْوَةً إلاَّ صَلَّى عَلَيهِ سَبْعُونَ أَلْفَ مَلَكٍ حَتَّى يُمْسِىَ وَإِنْ عَادَهُ عَشِيَّةً إِلَّا صَلَّى عَلَيهِ سَبْعُونَ أَلْفَ مَلَكٍ حَتَى يُصْبِحَ وَكَانَ لَهُ خَرِيفٌ فِي الْجَنَّةِ ( الترمذي 1/116 )
Hadhrat Ali (Radhiallahu Anhu) reports that Rasulullah (Sallallahu Alaihi Wasallam) said: “The one who visits a sick person in the morning, seventy thousand angels invoke Allah Ta’ala’s mercy for him until the evening, and the one who visits a sick person in the evening, seventy thousand angels invoke Allah Ta’ala’s mercy for him until the morning, and he will receive a garden in Paradise.
عَنْ أَبِي هُرَيرَةَ رَضِيَ اللهُ عَنهُ قَالَ قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيهِ وَسَلَّمَ مَنْ عَادَ مَرِيضًا نَادَى مُنَادٍ فِي السَّمَاءِ طِبْتَ وَطَابَ مَمْشَاكَ وَتَبَوَّأْتَ مِنَ الْجَنَّةِ مَنْزِلاً . (ابن ماجه ص104)
Hadhrat Abu Hurayrah (Radhiallahu Anhu) reports that Rasulullah (Sallallahu Alaihi Wasallam) said: Whosoever visits a sick person, an angel calls out from the sky: “May you remain in ease and comfort. How excellent is your walking (to meet your brother and show concern for him) and (through this action) you have built (for yourself) a palace in Jannah.”
2. Through visiting the sick one receives the pleasure of Allah Ta’ala.
عَن أبي هُرَيرَةَ رَضِيَ اللهُ عَنهُ قَالَ قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَليهِ وَسَلَّمَ : إِنَّ اللهَ عَزَّ وَجَلَّ يَقُولُ يَومَ القِيَامَةِ يَا ابْنَ آدَمَ مَرِضْتُ فَلَمْ تَعُدْنِي قَال يَا رَبِّ كَيفَ أَعُودُكَ وَأَنْتَ رَبُّ العَالَمِينَ قَالَ أَمَا عَلِمْتَ أَنَّ عَبْدِي فُلاَنًا مَرِضَ فَلَم تَعُدْهُ أَمَا عَلِمْتَ أَنَّكَ لَو عُدتَّهُ لَوَجَدتَّنِي عِنْدَهُ. (مسلم 2/318)
Hadhrat Abu Hurayrah (Radhiallahu Anhu) reports that Rasulullah (Sallallahu Alaihi Wasallam) said: “On the day of Qiyaamah, Allah Ta’ala will say, ‘O son of Aadam (Alaihis Salaam), I fell ill but you did not visit Me.’ The person will reply, ‘O Allah, how is it possible for me to visit You when You fall ill whereas You are the lord of the worlds.’ (i.e. You are not like human beings who fall ill). Allah Ta’ala will reply, ‘Don’t you know that My so and so slave had fallen ill and you did not visit him? Don’t you know that had you visited him you would have surely found Me present?’