Sayyiduna Abu Hurayrah (may Allah be pleased with him) said: When the Prophet (peace and blessings be upon him) went to the toilet, I would bring him water in a vessel. He (peace and blessings be upon him) would clean himself, then rub his hand on the ground. Then I would bring him another vessel, and he (peace and blessings be upon him) would perform ablution with it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 520