Abu Mūsa al-Ash‘ari (may Allah be pleased with him) reported: I came to the Prophet (may Allah's peace and blessings be upon him) while he was cleansing his mouth with a ripe tooth-stick. The edge of the tooth-stick was on his tongue and he was making a sound like: “ugh, ugh” as if he was heaving, and the tooth-stick was in his mouth.” Authentic hadith - Narrated by Bukhari & Muslim