Messenger of Allah (sal Allahu alaihi wa sallam) said, “The Muslim has six rights.
(1) When you meet him, you should greet him.
(2) When he invites you, you should accept his invitation.
(3) When he asks you for counsel, you should counsel him.
(4) When he sneezes and praises Allah, you should bless him.
(5) When he is ill, you should visit him.
(6) When he dies, you should follow him (i.e. his funeral procession).”
Attributed to Abu Hurairah (radi Allahu anhu)