"5 And the Lord spoke to Moses, saying, 6 “Take the Levites from among the people of Israel and cleanse them. 7 Thus you shall do to them to cleanse them: sprinkle the water of purification upon them, and let them go with a razor over all their body, and wash their clothes and cleanse themselves. 8 Then let them take a bull from the herd and its grain offering of fine flour mixed with oil, and you shall take another bull from the herd for a sin offering. 9 And you shall bring the Levites before the tent of meeting and assemble the whole congregation of the people of Israel. 10 When you bring the Levites before the Lord, the people of Israel shall lay their hands on the Levites, 11 and Aaron shall offer the Levites before the Lord as a wave offering from the people of Israel, that they may do the service of the Lord. 12 Then the Levites shall lay their hands on the heads of the bulls, and you shall offer the one for a sin offering and the other for a burnt offering to the Lord to make atonement for the Levites. 13 And you shall set the Levites before Aaron and his sons, and shall offer them as a wave offering to the Lord.
14 “Thus you shall separate the Levites from among the people of Israel, and the Levites shall be mine. 15 And after that the Levites shall go in to serve at the tent of meeting, when you have cleansed them and offered them as a wave offering. 16 For they are wholly given to me from among the people of Israel. Instead of all who open the womb, the firstborn of all the people of Israel, I have taken them for myself. 17 For all the firstborn among the people of Israel are mine, both of man and of beast. On the day that I struck down all the firstborn in the land of Egypt I consecrated them for myself, 18 and I have taken the Levites instead of all the firstborn among the people of Israel. 19 And I have given the Levites as a gift to Aaron and his sons from among the people of Israel, to do the service for the people of Israel at the tent of meeting and to make atonement for the people of Israel, that there may be no plague among the people of Israel when the people of Israel come near the sanctuary.”
20 Thus did Moses and Aaron and all the congregation of the people of Israel to the Levites. According to all that the Lord commanded Moses concerning the Levites, the people of Israel did to them. 21 And the Levites purified themselves from sin and washed their clothes, and Aaron offered them as a wave offering before the Lord, and Aaron made atonement for them to cleanse them. 22 And after that the Levites went in to do their service in the tent of meeting before Aaron and his sons; as the Lord had commanded Moses concerning the Levites, so they did to them."
Numbers 8:5-22
A good example of the concept of separation unto God may be seen in the incident recorded in 1 Samuel 8, which tells of Israel's insistence on having a king 'that we also may be like all the nations', an insistence that was to cost them dearly precisely because the whole point of their calling to be God's people was that they should not be like the other na- tions, but rather be God's peculiar people, separated unto Himself. It is significant that it was in those times when Israel most approximated to this separated character that they most fully realised their true destiny. The tragedy was that so often, particularly in the period of the kings, that separation was so substantially at a discount. If there is one general message for the Christian Church writ large on the pages of the Old Testament, it is that the people of God must take their call to spiritual nonconformity with the utmost seriousness. Only thus can they fulfil their destiny as lights in the world.
Nor is this separated existence to be regarded as cramping or restricting. Indeed it was the opposite for the Levites, for God said to them and of them, 'I am their inheritance', just as He has said earlier to Abraham, 'I am thy shield and thy exceeding great reward' (Genesis 15:1). God is no man's debtor, and it is those who, called to a one-track life, respond with wholehearted devotion, that live life most fully, and most interestingly too. One of the lessons that may be learned significantly from the lack of detail in the record of the lives of so many of the kings of Israel is that there is in fact nothing to record of lives that are outside the covenant purposes of God. They are dull and lifeless, even boring figures, lacking in sub- stance and vitality. It is the life thirled to the divine purposes that is really full and meaningful. Not only so: the separated life is also a life-giving, and fruit-bearing life. This is implicit in the idea of the Lord being their inheritance, and it finds its best and fullest expression in the Pauline statement in 2 Corinthians 6:10, 'As poor, yet making many rich'.