There is a peculiarity about this tithing, for while one-tenth was given to the Levites, they, the Levites, were commanded to give one-tenth of the tithe to Aaron.
"And the Lord spake unto Moses, saying. Thus speak unto the Levites, and say unto them. When ye take of the children of Israel the tithes which I have given you from them for your inheritance, then ye shall offer up an heave offering of it * * * for the Lord, even a tenth part of the tithe * * and ye shall give thereof the Lord's heave offering to Aaron the Priest." Num. xviii, 25-28.
It would seem that while the Levites were called "to do the service of the tabernacle of the congregation" (ver. 6), that the Priest's office belonged especially to Aaron and his family. The Lord, in speaking to Aaron, says, "And I, behold, I have taken your brethren the Levites from among the children of Israel: to you they are given as a gift for the Lord, to do the service of the tabernacle of the congregation."—Num. xviii, 6.
It furthermore appears that while the Levites were given to Aaron, that Aaron and his sons were to hold the Priest's office. "Therefore thou and thy sons with thee shall keep your Priest's office for everything of the altar, and within the vail; and ye shall serve: I have given your Priest's office unto you as a service of gift: and the stranger that cometh nigh shall be put to death."—Num. xviii, 7.
In the case of Korah, Dathan and Abiram, whom the earth opened and swallowed up for assuming the Priest's office, "Moses said unto Korah, hear, I pray you, ye sons of Levi: Seemeth it but a small thing unto you, that the God of Israel hath separated you from the congregation of Israel, to bring you near to himself to do the service of the tabernacle of the Lord, and to stand before the congregation to minister unto them? And he hath brought thee near to him, and all thy brethren the sons of Levi with thee: and seek ye the Priesthood also?"—Num. xvi, 8-10. And also the whole chapter, in which is depicted the terrible judgment of God upon them for assuming the Priest's office.
From the above it would seem—
First.—That the Levites were selected in the place of the firstborn whom the Lord called his own.
Second.—That they were given to Aaron to assist him in the minor or lesser duties of the Priesthood; but that Aaron and his sons officiated in the leading offices of the Priesthood, and not the Levites.
Third.—That there was a tithing paid to them by the whole house of Israel for their sustenance.
Fourth.—That they paid a tithe of this to Aaron.