The first is that it is food, based on the saying of Allah the Almighty: "Indeed, Allah will test you with a river. So whoever drinks from it is not of me, and whoever does not taste it is of me" (Quran 2:249). Food is that which is tasted. Also, because the Prophet (may Allah bless him and grant him peace) called milk food, yet it is a beverage, so it is the same for water. The second is that it is not food, because it is not termed food, nor is it understood from the general term "food"; for this reason, it is conjoined with it, as one says: "food and drink." The Prophet (may Allah bless him and grant him peace) said: "I do not know of anything that suffices as food and drink except milk." Narrated by Ibn Majah. It is also said: "The Chapter of Foods and Drinks." Moreover, even if it were food in reality, it is not food in custom, so he does not violate his oath by drinking it, because oaths are based on custom, as the swearer usually intends by his words only what he knows. If he eats medicine, there are two views: the first is that he violates his oath, because it is eaten in a state of choice, and this is the school of al-Shafi'i. The second is that he does not violate his oath, because it does not fall under the general term "food" and is not eaten except in case of necessity. If he eats something from the plants of the earth that is customarily eaten, he violates his oath. If he eats something that is not commonly eaten, such as tree leaves or wood shavings, there are two possibilities: the first is that he violates his oath, because he has eaten it, so it resembles that which is customarily eaten; and because it was narrated from Utba ibn Ghazwan that he said: "I have seen us with the Messenger of Allah (may Allah bless him and grant him peace), the seventh of seven, having no food but the leaves of the hubla (the fruit of the samur tree, resembling kidney beans) until our jaw sides became ulcerated." The second is that he does not violate his oath, because the term "food" does not apply to it by custom.