Musnad Ahmad 760:3

Husayn ibn Muhammad narrated to us, Muhammad ibn Mutarrif narrated to us, from Zayd ibn Aslam, from ‘Ata’ ibn Yasar, from Abu ‘Abd Allah al-Sunabihi, from the Prophet (peace and blessings of Allah be upon him), who said: "Whoever rinses his mouth and cleanses his nose, his sins exit from his nose and his mouth." He then mentioned its meaning.