The Messenger of Allah ﷺ said, "The Muslim has five rights over his fellow Muslim: returning the greeting of peace, visiting the sick, following funeral processions, accepting invitations, and responding to the one who sneezes."
قال رسول الله ﷺ: حق المسلم على المسلم خمس: رد السلام، وعيادة المريض، واتباع الجنائز، وإجابة الدعوة، وتشميت العاطس.
Bukhari narrated it in the Book of Funerals (1240), and Muslim in the Book of Greetings (4:2162), both through chains of transmission from Ibn Shihab, "Saeed bin Musayab told me, from Abu Hurairah," and he related it.