Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever sleeps with grease on his hand and does not wash it, and then something bites him, let him blame no one but himself."
(b) In the hadith of Suwayd bin al-Nu'man, the Prophet (peace and blessings be upon him) and the Companions (may Allah be pleased with them) rinsed their mouths after eating sawiq; and (as in) Kitab al-Taharah, the hadith about washing the hands after eating is hasan, while washing the hands before eating is (from) a da'if (weak) hadith.
(c) Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) went to the toilet, and when he came back, food was brought. It was said: "O Messenger of Allah, will you not perform wudu?" He (peace and blessings be upon him) said: "Why? When I pray, I will perform wudu."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14606