It is narrated from Sayyidah Maymunah (may Allah be pleased with her): I placed water for the Messenger of Allah's (peace and blessings be upon him) ritual bath for janabah (major impurity). He (peace and blessings be upon him) poured water over his right hand and washed it, then poured with his right hand over his left hand and washed it, then poured with his right hand over his left and washed his private part, then struck his hand on the ground, then performed ablution as for prayer, then poured water over his head with his hand three times, then over his whole body. Then, at a place apart from where he bathed, he washed his feet. I handed him a towel, but he did not take it and wiped his body with his hand.
(b) Hafs says: Al-A'mash mentioned this to his teacher Ibrahim, and he said: (It was declined) for fear that people would make it a habit.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 836