Musnad Ahmad 333:10

Bahz narrated to us, from Ikrimah ibn Ammar, who said: Iyas ibn Salamah ibn al-Akwa narrated to us, saying: My father narrated to me, saying: I was sitting with the Messenger of Allah, may Allah bless him and grant him peace, and a man sneezed. The Messenger of Allah, may Allah bless him and grant him peace, said: "May Allah have mercy on you." Then he sneezed again, and the Messenger of Allah, may Allah bless him and grant him peace, said: "The man has a cold."