What are the six rights of a muslim over another?
Book 026, Number 5379:
Abu Huraira reported Allah’s Messenger (may peace be upon him) as saying:
Six are the rights of a Muslim over another Muslim. It was said to him: Allah’s Messenger, what are these? Thereupon he said: When you meet him, offer him greetings;when he invites you to a feast accept it. when he seeks your council give him, and when he sneezes and says:” All praise is due to Allah,” you say Yarhamuk Allah (may Allah show mercy to you) ; and when he fails ill visit him; and when he dies follow his bier.
The Book on Salutations and Greetings (Kitab As-Salam)