(40) Sneezing and Yawning
كتاب الْعُطَاسَ والتثاؤب
(420) Chapter: What should someone who sneezes say first?
(420) بَابُ كَيْفَ يَبْدَأُ الْعَاطِسُ
Al-Adab Al-Mufrad 935 
Iyas ibn Salama related that his father said, "A man sneezed in the presence of the Prophet, may Allah bless him and grant him peace, and the Prophet said, 'May Allah have mercy on you.' Then the man sneezed again and the Prophet, may Allah bless him and grant him peace, said, 'This man has a cold.'"
حَدَّثَنَا عَاصِمُ بْنُ عَلِيٍّ، قَالَ‏:‏ حَدَّثَنَا عِكْرِمَةُ، قَالَ‏:‏ حَدَّثَنَا إِيَاسُ بْنُ سَلَمَةَ، عَنْ أَبِيهِ قَالَ‏:‏ عَطَسَ رَجُلٌ عِنْدَ النَّبِيِّ صلى الله عليه وسلم فَقَالَ‏:‏ يَرْحَمُكَ اللَّهُ، ثُمَّ عَطَسَ أُخْرَى، فَقَالَ النَّبِيُّ صلى الله عليه وسلم‏:‏ هَذَا مَزْكُومٌ‏.‏
Grade :  Sahih (Al-Albani) صـحـيـح  (الألباني)حكم :
Reference : Al-Adab Al-Mufrad 935
In-book reference : Book 40, Hadith 17
English translation : Book 40, Hadith 935