It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) drank milk, then rinsed his mouth and said: "It has fat in it."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 742
It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) drank milk, then called for water and rinsed his mouth, then said: "It has fat in it."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 743
Sayyiduna Suwayd bin al-Nu'man (may Allah be pleased with him) went out with the Prophet (peace and blessings be upon him) in the year of Khaybar. When he (peace and blessings be upon him) reached al-Sahba', a place on the lower side of Khaybar, he offered the Asr prayer; then he (peace and blessings be upon him) called for food, and nothing but sawiq (barley meal) was brought. He (peace and blessings be upon him) ordered that it be made into tharid; then he (peace and blessings be upon him) ate, and we ate with him too. Then he (peace and blessings be upon him) stood up for (the) Maghrib (prayer); he (peace and blessings be upon him) rinsed his mouth and we rinsed ours too; then he (peace and blessings be upon him) led the prayer but did not perform ablution.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 744