What is the ruling on visiting the sick and what are the Hadiths mentioned concerning it?

Visiting the sick is a right a Muslim has over his brother. The majority of scholars hold that it is a Sunnah (recommended practice), and it may reach the level of obligation for some individuals, while some scholars deem it obligatory. Many hadiths have been narrated encouraging it and explaining its reward, among them: "The rights of a Muslim over another Muslim are five," and "Feed the hungry, visit the sick, and free the captive." Among its merits are that whoever visits a sick person "remains in the harvest of Paradise until he returns," and "a caller proclaims to him: 'You are good, your walking is good, and you have taken a dwelling place in Paradise,'" and "seventy thousand angels supplicate for him."