Full Hadith
The Prophet (ﷺ) said, " If anyone of you sneezes, he should say 'Al-Hamduli l-lah' (Praise be to Allah), and his (Muslim) brother or companion should say to him, 'Yar-hamuka-l-lah' (May Allah bestow his Mercy on you). When the latter says 'Yar-hamuka-llah', the former should say, 'Yahdikumul-lah wa Yuslih balakum' (May Allah give you guidance and improve your condition).
Authentically sourced from Sahih Bukhari
This dua is from Sahih Bukhari (Hadith 6224), narrated by Abu Huraira. Every dua on Deen is sourced exclusively from the Quran, Sahih Bukhari, and Sahih Muslim. No personal opinions, no unverified content, no personal analysis.