Mishkat al-Masabih 21 Foods كتاب الأطعمة 22

وَعَنْ جَابِرٌ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ سَأَلَ أَهْلَهُ الْأُدْمَ. فَقَالُوا: مَا عِنْدَنَا إِلَّا خَلٌّ فَدَعَا بِهِ فَجَعَلَ يَأْكُلُ بِهِ وَيَقُولُ: «نِعْمَ الْإِدَامُ الْخَلُّ نِعْمَ الْإِدَامُ الْخَلُّ» . رَوَاهُ مُسلم

Jabir told th at when the Prophet asked his family for condiments and was told that they had only vinegar, he called for it and as he was using it in his food he said, “Vinegar is a good condiment; vinegar is a good condiment.” Muslim transmitted it.