Musnad Ahmad 937:277

Wahb ibn Jarir, ‘Arim, and Yunus narrated to us, they said: Mahdi ibn Maymun narrated to us, from Wasil, the freed slave of Abu ‘Uyaynah. ‘Arim said: Wasil narrated to us, from Yahya ibn ‘Aqil, from Yahya ibn Ya‘mar, from Abu al-Aswad al-Du’ali, from Abu Dharr, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The deeds of my nation were presented to me, their good ones and their bad ones. I found among the good of their deeds the removal of harm from the road, and I found among the bad of their deeds the phlegm." ‘Arim said: "That is in the mosque, not being buried." And Yunus said: "The phlegm is in the mosque, not being buried."