Not to eat untithed fruits

This mitzvah prohibits eating tevel, produce from which the various required tithes (terumah, ma’aser, challah, etc.) have not yet been separated. Until these portions are properly designated and given to the Kohanim and Levites, the produce remains forbidden for consumption. The law of tevel underscores the sanctity of agricultural produce, reminding Israel that the first portion of all sustenance belongs to Hashem. By tithing, one acknowledges divine ownership and transforms the remainder into permissible food.

Commentary & Classical Explanation:

• Rambam (Hilchot Ma’achalot Asurot 10:15): Codifies that eating tevel is a Torah prohibition and that all required separations must be made before consumption.
• Sefer HaChinuch (Mitzvah 485): The root is to recognize that our blessings come from Hashem, and giving tithes trains us in gratitude and generosity.
• Talmud (Berachot 36a): Declares that tevel is among the severest prohibitions, as it contains multiple unseparated sanctities.