Sunan An-Nasai, Chapter: The Book of Purification

Suwaid bin An-Numan said that he went out with the Messenger of Allah (saw) in the year of Khaibar, then when they were in As-Sahba '" which is the closest part of Khaibar '" he prayed Asr, then he called for food, and nothing was brought but Sawiq. He ordered that it be moistened with water, then he ate and we ate. Then he got up to (pray) Maghrib, and he rinsed his mouth and we rinsed our mouths, then he prayed and did not perform Wudu. (Sahih)