A man who sneezes alone: what does he say?

Husayn said: Ibrahim said: "When a person sneezes while he is alone, he should say: 'Alhamdulillahi Rabbil-alamin' (All praise is for Allah, the Lord of the worlds). Then he should say: 'Yarhamuna Allahu wa iyyakum' (May Allah have mercy on us and on you). For whoever of Allah's creation has heard his sneeze will have prayed for him by saying 'Yarhamuk Allah' (May Allah have mercy on you)."

Asim said: Abu Wa'il said: "When you sneeze while you are alone, respond to those who are with you, meaning the angels."