Jābir (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) asked his family for a dip (to eat with bread) and they replied: "We have nothing but vinegar." So he told them to bring it and began to eat, saying: "What an excellent dip vinegar is! What an excellent dip vinegar is!"
The Prophet (may Allah's peace and blessings be upon him) asked his family to bring him some food to eat it with bread. They replied that they had nothing but vinegar. So he asked them to bring it and started eating while praising vinegar and saying: "What an excellent dip vinegar is! What an excellent dip vinegar is!" This is a praise of vinegar. Although it is a drink, it is referred to as food. It is acceptable in Arabic to refer to anything that has a taste to be savored as food, as in the Qur'anic verse: {"Indeed, Allah will be testing you with a river. So whoever drinks from it is not of me, and whoever does not taste it is indeed of me.} [Sūrat al-Baqarah: 249]