صحيح البخاري Sahih Bukhari كتاب الأدب The Book of Al-Adab (Good Manners)
بَابُ لاَ يُشَمَّتُ الْعَاطِسُ إِذَا لَمْ يَحْمَدِ اللَّهَ:

(127) Chapter. Tashmit (may Allah be Merciful to you) should not be said to a sneezer if he does not say ‘AI-Hamdu-lillah’ (praise be to Allah).

1 hadith
Hadith 6225
حَدَّثَنَا آدَمُ بْنُ أَبِي إِيَاسٍ ، حَدَّثَنَا شُعْبَةُ ، حَدَّثَنَا سُلَيْمَانُ التَّيْمِيُّ ، قَالَ : سَمِعْتُ أَنَسًا رَضِيَ اللَّهُ عَنْهُ يَقُولُ : " عَطَسَ رَجُلَانِ عِنْدَ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ، فَشَمَّتَ أَحَدَهُمَا وَلَمْ يُشَمِّتِ الْآخَرَ ، فَقَالَ الرَّجُلُ : يَا رَسُولَ اللَّهِ ، شَمَّتَّ هَذَا وَلَمْ تُشَمِّتْنِي ، قَالَ : إِنَّ هَذَا حَمِدَ اللَّهَ وَلَمْ تَحْمَدِ اللَّهَ " .
Narrated Anas: Two men sneezed before the Prophet and he said Tashmit to one of them, while he did not say Tashmit to the other. So that man said, "O Allah's Apostle! You said Tashmit to that fellow but you did not say Tashmit to me. "The Prophet said, "That man praised Allah, but you did not praise Allah."
Hadith Reference Sahih Bukhari / The Book of Al-Adab (Good Manners) / Hadith: 6225
Hadith Grading محدثین: أحاديث صحيح البخاريّ كلّها صحيحة