3-123 Muhammad ibn al-Hassan ibn Ahmad ibn al-Walid - may God be pleased with him - narrated that Muhammad ibn al-Hassan al-Saffar quoted on the authority of Muhammad ibn al-Hussein ibn Abil-Khat’tab, on the authority of Ja’far ibn Bashir, on the authority of Abi Ayeenat, on the authority of Mansoor ibn Hazim that Aba Abdullah as-Sadiq (MGB) said, “On three occasions one is prayed for in the plural although he is singular. The first occasion is when one sneezes. They tell him ‘Yarhamakumullah that means ‘May God have Mercy upon you’ as if someone else is with him. The second occasion is when one greets others. They return his greeting by saying ‘Assalumalaykum as if others are with him. The third occasion is when one prays for someone else to be healed and says ‘Afakumullah as if he is praying for more than one person.”The compiler of the book - may God increase his honor - said, “They say ‘Yarhamakumullah to the opponents once they sneeze which refers to the two appointed accompanying angels, but say ‘Yarhamakullah to a believer when he sneezes.”