The Jews used to try to sneezes in the presence of the Prophet (ﷺ) hoping that he would say to them: "Allah have mercy on you!" but he would say: May Allah guide you and grant you well-being!
Sunan Abi Dawud Book 43, Hadith 266
← Previous Hadith when a man sneezed beside the prophet (May peace be upon him), he said to him : Allah have mercy on you, but when he sneezed again, he said : The man has a cold in the head.

Sunan Abi Dawud Book 43, Hadith 265 Next Hadith → 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.

Sunan Abi Dawud Book 43, Hadith 267