It has been reported that the Prophet [a.s] said:

Whenever a believer visits one who is sick for the sake of Allah, he will be immersed in mercy totally. When he sits and spends some time with him, he will be soaked in mercy completely. If he visits him in the morning, seventy thousand angels will bless him until he retires in the evening; and if he visits him at night, seventy thousand angels will bless him until he rises in the morning.
 It has been reported that Abu 'Abd Allah [a.s] said:

If a believer visits his fellow believer when he is sick, seventy-seven thousand angels will pray for him; and if he sits with him a while, he will be inundated with mercy, and the angels seek forgiveness for him until he retires in the evening; and if he visits in the evening, it shall be the same for him until he rises in the morning.
 It has been reported that Abu Ja'far [a.s] said:

When a Muslim servant (of Allah) leaves his home intending to visit his brother for the sake of none but Allah, seeking the pleasure of Allah and hoping for what (reward) is with Him, Allah will appoint seventy thousand angels calling out from behind him until he returns home (saying), 'Rejoice and enjoy Paradise!'
 It has been related that Amir al-Mu'minin [a.s] said to some of his companions, 'Will you come with me to visit so-and-so who is sick?' They therefore went with him and found Abu Musa al-Ash'ari seated with him. Amir al-Mu'minin [a.s] asked, 'O Abu Musa, have you come to see him because he is sick or is it just a social visit?' 'Rather (I came) because he is sick,' he replied.

'When a believer visits his sick brother-in-faith,' Amir al-Mu'minin [a.s] said, 'seventy thousand angels bless him until he returns to his family.'

 It has been related that Abu Ja'far, on the authority of his fathers, narrated that Al-Husayn ibn 'Ali [a.s] said that the Prophet [a.s] narrated:

Archangel Gabriel narrated to me that Allah [M.G] once sent down an angel who walked up to a house door where a man stood seeking permission to enter. The angel said to him, 'What do you want from the owner of this house?' 'He is my Muslim brother. I am visiting him for the sake of Allah,' he replied. 'No other motive has brought you, has it not?' asked the angel. 'None whatsoever,' replied the man. 'I am a messenger from Allah to you,' said the angel, 'He sends you greetings saying: I have made Paradise for you undoubtedly.

'Allah says,' added the angel, 'any Muslim who visits a fellow Muslim has in fact visited Me and his reward shall be Paradise.'

 It has been reported that Abu 'Abd Allah [a.s] said: the Messenger of Allah [a.s] said, May I inform you of the people amongst you that are the people of Paradise?' 'Indeed, O Messenger of Allah,' they replied. 'They are the Prophets,' he said, 'the truthful, the martyrs, the newborns and those who visit their brothers at far away places in the city for no reason except seeking the pleasure of Allah.'

 It has been related that Abu Hamzah said: I heard al-'Abd al-Salih (The righteous servant of Allah; namely, Imam al-Kad(im [a.s]) saying:

One who visits his fellow believer for no reason other that seeking Allah's pleasure and reward and fulfilling the pledges to obey Him, Allah will appoint for him seventy thousand angels from the time he leaves his house to the time he returns, calling out to him, 'Rejoice and enjoy Paradise. You have reserved a place in it!'

 It has been reported that Abu 'Abd Allah [a.s] said:

When one visits his brother-in-faith, the Lord [M.G] says, 'O you who are visiting! Rejoice and enjoy Paradise.'

It has been reported that Abu 'Abd Allah [a.s] said: the Messenger of Allah [a.s] said:

Any Muslim who visits a sick believer will be absorbed in mercy. When he sits with him (the sick believer), mercy will submerge him; and when he returns, he will be accompanied by seventy thousand angels until he enters his house, every one of them saying, 'Rejoice and enjoy Paradise.'

 It has been reported that Abu Ja'far [a.s] said:

Allah has a Paradise that none shall enter except three kinds of people: one who judges concerning himself with justice, one who visits his fellow righteous believer and one who does good for his fellow believer for the sake of Allah.

It has been narrated that Abu Ja'far and Abu 'Abd Allah [a.s] both said:

On the Day of Resurrection, when a believing servant comes before Allah, He will account him with an easy accounting but then reproach him saying, 'O believer, what stopped you from visiting Me when I was sick?' The believer shall reply, 'You are my Lord and I am Your servant; and You are ever-living and never afflicted with suffering or illness!' 'One who visits a believer in sickness has in fact visited Me,' shall say the Lord [M.G], 'Do you not know so-and-so?' 'Yes,' the believer shall reply, 'I know him.' Allah [M.G] shall then say, 'What stopped you from visiting him when he was sick? Had you visited him, you would have visited Me. Then you would have found Me ever-present at the time of your need. If you then would have asked me for any need, I would have fulfilled it for you and not turned you away from it.'

 It has been narrated that Abu Ja'far said:

An angel once passed by a man standing at the door of a house. He asked, 'Servant of Allah, what brings you here?' 'My brother lives here,' replied the man, 'I intend to greet him.' 'Is there any blood relation between you or has a need brought you to him?' asked the angel. 'No,' answered the man, 'we are neither related nor has a need brought me to him except our Islamic brotherhood and respect for him. I am acquainted to him and I greet him only for the sake of Allah; the Lord of the worlds.' The angel said, 'I am a messenger of Allah to you and He sends you greetings saying to you: It is in fact I that you have visited and it is I that you have approached; and for that, I have made Paradise mandatory for you, put off My wrath from you and protected you from the Fire (of Hell).

 It has been reported that Abu Ja'far [a.s] said:

Any believer who visits a believer has in fact visited Allah; 176 and any believer who visits a sick believer will be immersed in mercy. When he sits with the sick believer, mercy will inundate him; and when he leaves, Allah [M.G] will appoint for him seventy thousand angels who seek forgiveness and mercy for him, saying, 'Rejoice and enjoy Paradise' until the same time the next day and he shall have a kharif in Paradise.'

The narrator asked, 'May I be ransomed for you, what is a kharif?'

'Kharif is a corner in Paradise,' he replied, 'It would take a rider forty years to journey through.'