Shaykh Ibn 'Uthaymeen explains that the foundational principle (al-asl) concerning foods and drinks is that they are all permissible (halal), unless there is specific evidence from the Qur'an or authentic Sunnah that proves them to be forbidden (haram).

Based on this, we do not need to ask for the evidence for something being halal, because its original state is permissibility. Rather, the question should be about what is haram, and the evidence required is for the prohibition.

The primary categories of haram foods are those explicitly mentioned in the Qur'an: "Prohibited to you are carrion, blood, the flesh of swine, and that which has been dedicated to other than Allah, and [those animals] killed by strangling or by a violent blow or by a fall or by being gored or by being [partly] eaten by a wild animal - except for what you [are able to] slaughter [before its death]..." ([Surah Al-Ma'idah 5:3](/quran/5/3))

This verse outlines several prohibitions:

1. Carrion (Al-Maytah): An animal that dies a natural death without being properly slaughtered.
2. Blood (Ad-Dam): This refers to flowing, liquid blood, not the small amount that remains in the veins and meat after slaughter.
3. Pork (Lahm al-Khinzeer): The flesh of pigs and all their derivatives.
4. That which is dedicated to other than Allah: Animals slaughtered in the name of an idol, saint, or anything other than Allah.

The Sunnah adds further prohibitions, most notably:

• Predatory animals with fangs: Such as lions, tigers, wolves, and dogs.
• Birds with talons: Such as eagles, hawks, and falcons.
• The domestic donkey.

Any food that does not fall into these or other specifically prohibited categories is considered halal and may be consumed. Seafood, for example, is entirely halal, as is all vegetation that is not harmful or intoxicating. If there is doubt about a food and no clear text prohibiting it, the principle of default permissibility applies.