Musnad Ahmad 5:112

Abu Sa’id narrated to us, Isra’il narrated to us, from Abu Ishaq, from al-Harith, from ‘Ali, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "The Muslim has six [rights] of kindness over the Muslim: He greets him when he meets him, he responds to him [with 'Yarhamuk Allah'] when he sneezes, he visits him when he is sick, he answers him when he calls him, he attends his [funeral] when he dies, and he loves for him what he loves for himself, and he is sincere to him in his absence."