Abu Burda reported,

I entered upon Abu Musa while he was in the house of the daughter of Fadl bin Abbas. I sneezed, and he did not bless me, then she sneezed, and he blessed her. I went back to my mother and told her what had happened.When he came to her, she said, "My son sneezed in your presence and you did not bless him, yet she sneezed and you blessed her."He replied, "Your son sneezed but did not praise Allah, so I did not bless him. She sneezed and praised Allah, so I blessed her. I heard the Messenger of Allah ﷺ say, 'When one of you sneezes and praises Allah, bless him. But if he does not praise Allah, do not bless him.'"

Azami 14142

Sahih

عن أبي بردة، قال

دخلت على أبي موسى وهو في بيت بنت الفضل بن عباس فعطست فلم يشمتني، وعطست فشمتها، فرجعت إلى أمي فأخبرتها، فلما جاءها قالت: عطس عندك ابني فلم تشمته، وعطست فشمتها، فقال: إن ابنك عطس، فلم يحمد الله، فلم أشمته، وعطست فحمدت الله فشمتها، سمعت رسول الله ﷺ يقول: إذا عطس أحدكم فحمد الله، فشمتوه، فإن لم يحمد الله، فلا تشمتوه.

الأعظمي 14142صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Superior moral conduct
Chapter
Characteristics of Muslims, and their rights upon one another
Section
Not responding to the one who sneezes if he does not praise Allah
Numbering
Jami al-Kamil 14142 (2nd edition)
Azami 14142