NUM241 The Levites shall give a tithe of their tithe to the Kohanim. Hashem chose the tribe of Levi to serve in the Beis HaMikdash on a permanent and constant basis., but He chose one of them in particular, Aharon, to be the Kohen, chief of staff over everyone else. Aharon and his descendants are the Kohanim for all time, and they, too, are permanently appointed to stand before Hashem in the Beis HaMikdash on a steady basis. In fact, the main avodah in the Beis HaMikdash is the task of the Kohanim. The Levites are secondary to the Kohanim and are there to assist them. Since the Kohanim perform the main avodah in the House of our God, they receive twenty-four gifts. The Levites, as assistants of the Kohanim, also merit good without toil in the form of ma’aser rishon from the rest of the tribes of Israel, from which the Levites have nourishment. So that the Levites appreciate that their goodly portion is due only to their service in the House of God, they are commanded to give one-tenth of their portion to the Kohanim-- those who attend to the main avodah in the House of God. Thereby, the Levites will recognize that there are others over them, and above everyone is God Himself. Also, this mitzvah provides merit and honor to the Levites, for they are not denied the mitzvah of giving ma’aser. They, too, have a share in providing sustenance to the Kohanim.