Sayyiduna Usamah bin Zayd (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) entered "al-Aswaf" and went to relieve himself, and Sayyiduna Bilal (may Allah be pleased with him) was with him. When they came out, I asked Bilal (may Allah be pleased with him): What did he (peace and blessings be upon him) do? He said: "He (peace and blessings be upon him) performed ablution: he washed his face and his hands, wiped his head, and also wiped over his leather socks." This hadith is sahih (authentic) on the condition of Imam Muslim, because he used Dawud bin Qays as evidence.