It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that he said: I saw the Prophet (peace and blessings be upon him) eating the meat off a goat's bone; then he (peace and blessings be upon him) prayed, and he neither rinsed his mouth nor touched water.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 745