Sahih Adab al-Mufrad

724/941- (Sahih) From Abu Burda who said: I entered upon Abu Musa – while he was in the house of [ابنته](1) Umm al-Fadl bint al-Abbas – and I sneezed, but he did not respond to my sneeze. She sneezed, and he responded to her. I informed my mother, and when he came to her, she confronted him and said: My son sneezed and you did not respond to him, but she sneezed and you responded to her. He said to her: I heard the Prophet, peace and blessings be upon him, say: "If one of you sneezes and praises Allah, then respond to him; but if he does not praise Allah, then do not respond to him." Your son sneezed and did not praise Allah, so I did not respond to him; she sneezed and praised Allah, so I responded to her. She said: You did well.