Hadith 2991 a - The Book of <i>Zuhd</i> and Softening of Hearts - Sahih Muslim - صحيح مسلم - Collection of Actions, Sayings and Teachings of Prophet Muhammad (صلى الله عليه و سلم) - Kutub as-Sittah

55. The Book of Zuhd and Softening of Hearts - كتاب الزهد والرقائق

9) Chapter: Saying: "May Allah Have Mercy On You" To One Who Sneezes, And Yawning Is Disliked

Anas b. Malik reported that two persons sneezed in the presence of Allah's Messenger (ﷺ). He (the Messenger of Allah) invoked mercy for one, and did not invoke for the other. The one for whom he had not prayed said:

So and so sneezed and you said: May Allah have mercy upon you. I also sneezed but you did not utter these words for me. Thereupon he (the Holy Prophet) said: That person praised Allah, and you did not praise Allah.

Reference: 2991 a
English reference: Book 42, Hadith 7125
In-book reference: Book 55, Hadith 69
Grade: Sahih
Read this hadith from Darussalam Collection

9) باب تَشْمِيتِ الْعَاطِسِ وَكَرَاهَةِ التَّثَاؤُبِ

حَدَّثَنِي مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، حَدَّثَنَا حَفْصٌ، - وَهُوَ ابْنُ غِيَاثٍ - عَنْ سُلَيْمَانَ، التَّيْمِيِّ عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ عَطَسَ عِنْدَ النَّبِيِّ صلى الله عليه وسلم رَجُلاَنِ فَشَمَّتَ أَحَدَهُمَا وَلَمْ يُشَمِّتِ الآخَرَ فَقَالَ الَّذِي لَمْ يُشَمِّتْهُ عَطَسَ فُلاَنٌ فَشَمَّتَّهُ وَعَطَسْتُ أَنَا فَلَمْ تُشَمِّتْنِي ‏.‏ قَالَ ‏‏ ‏.‏ "‏ إِنَّ هَذَا حَمِدَ اللَّهَ وَإِنَّكَ لَمْ تَحْمَدِ اللَّهَ ‏"