Sayyiduna Abu Hurairah, may Allah be pleased with him, narrates: A man passed by the Prophet, peace and blessings be upon him. At that time, the Prophet, peace and blessings be upon him, was sitting in a gathering. He said: Peace be upon you. The Prophet, peace and blessings be upon him, said: He received ten good deeds. Then another man passed by and said: Peace be upon you and the mercy of Allah. The Prophet, peace and blessings be upon him, said: Twenty good deeds. Then another man passed by and said: Peace be upon you and the mercy of Allah and His blessings. The Prophet, peace and blessings be upon him, said: Thirty good deeds. Then one of those present stood up and did not offer greetings, so the Prophet, peace and blessings be upon him, said: It is possible that your companion did not forget (to greet). Whoever comes to a gathering should offer greetings; if he wishes, he may sit there, and if he wishes to leave, he should offer greetings again, because the first is not more entitled than the second.