Sunan Abi Dawud, Hadith 5015 ⓘ
Abu Hurairah reported the prophet (May peace be upon him) as saying: When one of you sneezes, he should say: "Praise be to Allah in every circumstance," and his brother or his companion should say: "May Allah have mercy on you!" And he should then reply: "May Allah guide you and set right your affairs."
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ عَبْدِ اللَّهِ بْنِ أَبِي سَلَمَةَ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " إِذَا عَطَسَ أَحَدُكُمْ فَلْيَقُلِ الْحَمْدُ لِلَّهِ عَلَى كُلِّ حَالٍ وَلْيَقُلْ أَخُوهُ أَوْ صَاحِبُهُ يَرْحَمُكَ اللَّهُ وَيَقُولُ هُوَ يَهْدِيكُمُ اللَّهُ وَيُصْلِحُ بَالَكُمْ " .
also referenced under: Hadith 5033 (DarusSalam) & Book 41, Hadith 5014 (USC-MSA)