When one of you sneezes, you should say:
(All praise be to Allah)
When you hear a person sneeze and say 'al-hamdu-lillaah', you should reply:
(May Allah have mercy upon you)
If you hear a person say 'Yarhamukallaah', you should say:
Yahdikumullaahu wa yuslihu baalakum
(May Allah guide you and straighten your affairs)
- It is narrated on the authority of Abu Hurayrah  that the Prophet of Allah  said: "When one of you sneezes, let him say, al-hamdu-lillaah ('All praise be to Allah'). And let his brother or companions say to him, yarhamukallaah ('May Allah have mercy upon you'), and if he says, yarhamukallaah, let him say, yahdikumullaahu wa yuslihu baalakum ('May Allah guide you and straighten your affairs')."