Sunan an-Nasa'i, Hadith 3796 ⓘ
It was narrated that Jabir said: "I entered the house of the Prophet with him and there was some bread and vinegar. The Messenger of Allah said: 'Eat; what a good condiment is vinegar.'"
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا الْمُثَنَّى بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا طَلْحَةُ بْنُ نَافِعٍ، عَنْ جَابِرٍ، قَالَ دَخَلْتُ مَعَ النَّبِيِّ صلى الله عليه وسلم بَيْتَهُ فَإِذَا فِلَقٌ وَخَلٌّ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " كُلْ فَنِعْمَ الإِدَامُ الْخَلُّ " .
also referenced under: Book 35, Hadith 36 (In-Book) & Volume 4, Book 35, Hadith 3827 (DarusSalam)