The tribe of Levi is the only tribe not given land. God is to be their inheritance. The ‘Kohanim,’ Priests, and Levites are to have the special role of serving in the Holy Temple and teaching God’s Torah to the Jewish People. The Jewish People as a whole have the obligation to support them. This is to be done through giving them special gifts from all produce grown in the Land of Israel. In the case of the ‘Kohanim,’ they also are to receive portions of certain sacrifices. Although these gifts are not given in our era, Jews still separate a small amount of all produce grown in Israel. The continuation of this practice is a constant reminder of the sacred obligation to make sure that all members of society have sufficient food.
Source: Israel in the News