Musnad Ahmad 32:855

Isma'il narrated to us, Sulayman al-Taymi narrated to us, Anas narrated, he said: Two men sneezed in the presence of the Prophet, may Allah bless him and grant him peace. He said: He blessed one of them—or he said: He prayed for one of them—and left the other. It was said: They are two men who sneezed, and you blessed one of them—or he said: You prayed for one of them—and left the other. He said: "Indeed, this one praised Allah, and this one did not praise Allah." Sulayman said: "I think it is something like this."