It is narrated from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that he said:
"We took part with the Messenger of Allah (peace and blessings be upon him) in one of our military expeditions, and he (peace and blessings be upon him) came to a pool. The Messenger of Allah (peace and blessings be upon him) encamped there and we encamped too, and the time of prayer came. The Messenger of Allah (peace and blessings be upon him) said: 'O Bilal, stand and call the adhan.' So Sayyiduna Bilal (may Allah be pleased with him) went and relieved himself, then came to the pool, washed his face and his two hands, and bent down towards his leather socks. He was wearing two black leather socks, and all this was happening before the eyes of the Messenger of Allah (peace and blessings be upon him). Then the Messenger of Allah (peace and blessings be upon him) called out to him and said: 'O Bilal, wipe over the leather socks and the turban.'"
Hadith Referenceالمعجم الأوسط / باب الألف / 1037
Hadith Gradingمحدثین:إسناده ضعيف لضعف غسان بن عوف
Hadith Takhrij«قال الهيثمي: فيه غسان بن عوف قال الأزدي ضعيف «مجمع الزوائد ومنبع الفوائد، ج 1، ص 256»»