Hadith #5039 (Sunan Abi Dawud)
Book: General Behavior (Kitab Al-Adab)
Narrator(s): Muhammad bin al-Muthna - al-Zaman محمد بن المثنى أبو موسى - الزمن, Salm bin Nwh bin Aby سالم بن نوح بن أبي, Umar bin Jabir al-Yemami عمر بن جابر اليمامي
Grade: Sahih

Two men sneezed in the presence of the prophet (May peace be upon him). He said : Allah have mercy on you! To one and not to the other. He was asked: Messenger of Allah! Two persons sneezed. Ahmad’s version has: You invoked a blessing on one of them and left the other. He replied : This man praised Allah, and this man did not praise Allah.

Source: https://parallelquran.com/hadith/sunan-abi-dawud-5039/