במדבר, פרק י״ח, פסוק כ״ו

The dedication of the Levite tribe to holy service required them to forfeit a physical portion of land in Israel. In exchange for their labor, they received the first tenth of the nation's agricultural produce. Yet, the act of receiving this gift carried its own obligation. The Levites were required to separate a portion from their own received crops and present it to the priests, acknowledging both the holiness of God and the elevated status of the priesthood.

The primary approach among commentators is that this initial agricultural gift is intended exclusively for the Levites, as the priests receive separate offerings of their own. However, some maintain that priests are also included in this entitlement, a view that gained practical weight later in history when Ezra the Scribe penalized the Levites and redirected these portions to the priests. The instruction to the Levites carries an educational warning against arrogance. Even though they are supported by the nation's gifts, they must not view themselves as equal to Aaron the Priest. In this context, they are considered no different than ordinary Israelites who are obligated to separate a portion of their harvest, and they must maintain a sense of gratitude toward the priests [שפתי כהן].

The obligation to separate this portion applies exclusively to crops grown by Israelites, exempting any produce acquired from non-Jews. Furthermore, an offering is never extracted from someone who already possesses it by right; therefore, a priest who purchases produce is not required to give a tenth to a Levite. The agricultural gift serves as a direct substitute for the physical territory the Levites lacked. Some commentators note a precise calculation in this arrangement: had the Levites settled the land, they would have received one portion out of the twelve tribes. Receiving a tenth of the national yield, minus the single percent they pass on to the priest, leaves them with an amount exactly equal to the inheritance they would have otherwise claimed [הכתב והקבלה]. Because it replaces a permanent land inheritance, this provision is constant. It is given to the Levites every single year, even during years when the general distribution of agricultural gifts shifts to benefit the poor, ensuring they always have their sole source of livelihood.

The physical act of separating the offering involves several practical laws. The portion must be taken only from harvested produce, not from crops still attached to the soil. The separation must also be exact in its nature; it is forbidden to substitute one species for another, or to exchange newly harvested crops for older ones. Nevertheless, if an improper separation occurs after the fact, such as using ritually impure fruit to exempt pure fruit, the designation remains valid.

The required contribution is exactly one tenth of the received portion, amounting to one percent of the total overall harvest, and is recognized as God's sacred offering. If a Levite happens to collect his portion early, while the grain is still in its stalks and before the threshing process that normally triggers the farmer's obligation to give a primary offering to the priest, the Levite is exempt from fulfilling that broader obligation. In such a case, he is only required to transfer his specific tenth to the priest.