Sahih Bukhari Volume 7, Book 70, Hadith 5456

حَدَّثَنَا عَلِيٌّ، حَدَّثَنَا سُفْيَانُ، سَمِعْتُ يَحْيَى بْنَ سَعِيدٍ، عَنْ بُشَيْرِ بْنِ يَسَارٍ، عَنْ سُوَيْدِ بْنِ النُّعْمَانِ، قَالَ خَرَجْنَا مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم إِلَى خَيْبَرَ، فَلَمَّا كُنَّا بِالصَّهْبَاءِ دَعَا بِطَعَامٍ فَمَا أُتِيَ إِلاَّ بِسَوِيقٍ، فَأَكَلْنَا فَقَامَ إِلَى الصَّلاَةِ، فَتَمَضْمَضَ وَمَضْمَضْنَا‏.‏

Narrated By Suwaid bin An Nu'man : We went out with Allah's Apostle to Khaibar, and when we reached As-Sahba', the Prophet asked for food, and he was offered nothing but Sawiq. We ate, and then Allah's Apostle stood up for the prayer. He rinsed his mouth with water, and we too, rinsed our mouths.