Al-Adab Al-Mufrad, Book 40, Hadith 941 (In-Book) ⓘ

Abu Burda said, "I came to Abu Musa while he was in the house of Umm al-Fadl ibn al-'Abbas and I sneezed and Abu Musa did not wish mercy on me. Umm al-Fadl sneezed and he wished mercy on her. I told my mother, so when Abu Musa came to her, she confronted him and said, 'My son sneezed and you did not wish mercy on him. She (Umm al-Fadl) sneezed and you wished mercy on her.' Abu Musa replied, 'I heard the Prophet, may Allah bless him and grant him peace, say, "When one of you sneezes and praises Allah, you should wish mercy on him, if he does not praise Allah, do not wish mercy on him." My son sneezed and did not praise Allah, so I did not wish mercy on him. She sneezed and praised Allah, so I wished mercy on her.' She said, 'You did well.'"

حَدَّثَنَا فَرْوَةُ، وَأَحْمَدُ بْنُ إِشْكَابَ، قَالاَ‏:‏ حَدَّثَنَا الْقَاسِمُ بْنُ مَالِكٍ الْمُزَنِيُّ، عَنْ عَاصِمِ بْنِ كُلَيْبٍ، عَنْ أَبِي بُرْدَةَ قَالَ‏:‏ دَخَلْتُ عَلَى أَبِي مُوسَى، وَهُوَ فِي بَيْتِ ابْنَتِهِ أُمِّ الْفَضْلِ بْنِ الْعَبَّاسِ، فَعَطَسْتُ فَلَمْ يُشَمِّتْنِي، وَعَطَسَتْ فَشَمَّتَهَا، فَأَخْبَرْتُ أُمِّي، فَلَمَّا أَتَاهَا وَقَعَتْ بِهِ وَقَالَتْ‏:‏ عَطَسَ ابْنِي فَلَمْ تُشَمِّتْهُ، وَعَطَسَتْ فَشَمَّتَّهَا، فَقَالَ لَهَا‏:‏ إِنِّي سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ‏:‏ إِذَا عَطَسَ أَحَدُكُمْ فَحَمِدَ اللَّهَ فَشَمِّتُوهُ، وَإِنْ لَمْ يَحْمَدِ اللَّهَ فَلاَ تُشَمِّتُوهُ، وَإِنَّ ابْنَكِ عَطَسَ فَلَمْ يَحْمَدِ اللَّهَ، فَلَمْ أُشَمِّتْهُ، وَعَطَسَتْ فَحَمِدَتِ اللَّهَ فَشَمَّتُّهَا، فَقَالَتْ‏:‏ أَحْسَنْتَ‏.‏