Narrated Abu Ayyub:
that the Messenger of Allah (ﷺ) said: "When one of you sneezes let him say: 'Al-Hamdulillahi 'Ala Kulli Hal (All praise is due to Allah in every circumstance).' And let the one replying to him say: "Yarhamukallah (May Allah have mercy upon you).' And let him say to him: 'Yahdikumullah Wa Yuslihu Balakum (May Allah guide you and rectify your affairs).'"
English reference: Vol. 5, Book 41, Hadith 2741
Arabic reference: Book 43, Hadith 2960