Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, who says that the Messenger of Allah, peace and blessings be upon him, said: “A Muslim has five rights over another Muslim: returning the greeting of peace, accepting an invitation, following funeral processions, visiting the sick, and responding to the sneeze of one who sneezes, provided he says «اَلْحَمْدُ لِلّٰهِ».”