Musannaf Ibn Abi Shaybah

Hazrat Mus'ab bin Abdur Rahman bin Dhuyaib narrates that a man sneezed in the presence of Hazrat Ibn Zubair, so he prayed for him by saying "Yarhamukallah." When he sneezed again, he prayed for him again by saying "Yarhamukallah." When he sneezed a third time, he again prayed for him by saying "Yarhamukallah." Then, when he sneezed a fourth time, Hazrat Abdullah bin Zubair said to him: "Surely, you are suffering from a cold; you should clean your nose."