[Exodus 28:41] You shall anoint them and ordain them and consecrate them, that they may serve Me as priests.

The Levitical priesthood is forever. God loves His priests so much that He exchanged the firstborn for His priests. [Numbers 3:12, 41, 45; 8:16 & 18] Now, behold, I have taken the Levites from among the sons of Israel instead of every firstborn, the first issue of the womb among the sons of Israel. So the Levites shall be Mine.

Moreover, all the tithe belonged to the Levite God’s minister. Prophet Malachi specifically speaks of the provision of the spiritual food and not the perishing daily bread.

[Malachi 3:10] Bring the whole tithe into the storehouse, so that there may be food in My house, and test Me now in this,” says the LORD of hosts, “if I will not open for you the windows of heaven and pour out for you a blessing until it overflows.”

The tithe for God’s chosen ministers represents their inheritance through which God tests people's hearts whether they would be compassionate and gracious.

[Numbers 18:21-24] To the sons of Levi, behold, I have given all the tithe in Israel for an inheritance, in return for their service which they perform, the service of the tent of meeting. [22] The sons of Israel shall not come near the tent of meeting again, or they will bear sin and die. [23] Only the Levites shall perform the service of the tent of meeting, and they shall bear their iniquity; it shall be a perpetual statute throughout your generations, and among the sons of Israel they shall have no inheritance. [24] For the tithe of the sons of Israel, which they offer as an offering to the LORD, I have given to the Levites for an inheritance; therefore I have said concerning them, ‘They shall have no inheritance among the sons of Israel.’

The Levitical priestly anointing is also perpetual. It cannot ever be taken back, but just as it is written “Only the Levites shall perform the service of the tent of meeting, and they shall bear their iniquity” so this office carries great responsibility. The anointed should not be selfish or conceited, for he is God’s minister serving His people.