Sahih al-Bukhari 5454
Narrated Suwaid bin An Nu`man:
We went out with Allah's Messenger (ﷺ) to Khaibar, and when we reached As-Sahba', the Prophet (ﷺ) asked for 
food, and he was offered nothing but Sawiq. We ate, and then Allah's Messenger (ﷺ) stood up for the prayer. 
He rinsed his mouth with water, and we too, rinsed our mouths.
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.‏