What is the authenticity of a Muslim's saying, after responding to a sneezer with "yarhamukallah (may Allah have mercy on you)": "yarhamuna wa yarhamukumullah (may Allah have mercy on us and on you all)" or "hadana wa hadakumullah (may Allah guide us and guide you all)"? And were these forms reported from the Prophet, peace and blessings be upon him? And what are the correct forms that have been reported?

The glorification of Allah by the sneezer and the reply to the one who says "Yarhamukallah (May Allah have mercy on you)" are narrated with different wordings. The sneezer says: "Alhamdulillah (All praise is due to Allah)," or "Alhamdulillah ala kulli hal (All praise is due to Allah in every circumstance)," or "Alhamdulillah Rabbil-alamin (All praise is due to Allah, Lord of the worlds)." The one who says "Yarhamukallah" says: "Yarhamukallah." And the sneezer replies to him: "Yahdikumullah wa yuslihu balakum (May Allah guide you and rectify your affairs)," or "Yaghfirullahu lana wa lakum (May Allah forgive us and you)." All these wordings are correct and established.