It is narrated from Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Feed the hungry, visit the sick, and set free the captive." Sufyan (may Allah have mercy on him) said: "Al-'ani" means the captive.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6575
Sayyiduna Abu Musa (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) said: "Secure the release of captives.
Accept the invitation of the one who invites you, and visit the sick."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6576
Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) "commanded us to do seven things: 1 to visit the sick, 2 to follow funerals, 3 to respond to one who sneezes, 4 to return the greeting of salam, 5 to accept invitations, 6 to fulfil oaths, and 7 to help the oppressed."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6577
Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Visit your sick and follow funerals; this will remind you of the Hereafter."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6578