Sahih al-Bukhari 2731, 2732

[…] `Urwa then started looking at the Companions of the Prophet. By Allah, whenever Allah’s Messenger spat, the spittle would fall in the hand of one of them (i.e. the Prophet’s companions) who would rub it on his face and skin; if he ordered them they would carry his orders immediately; if he performed ablution, they would struggle to take the remaining water;

The History of Al-Tabari, tr. & ann. by Michael Fishbein (1997), Vol 08; page 77

‘Urwah began looking at the companions of the Prophet. “By God,” he said, “if the Prophet coughs up a bit of phlegm and it falls onto the hand of one of them, he rubs his face and skin with it.