FROM SINAI ON, the Levites are treated differently from the other tribes: they alone handle the tabernacle and its accoutrements, from them come the priests, they are not given a separate allotment of land but are dispersed throughout the nation, and so forth.
But here in Numbers 3, one of the most startling distinctives is portrayed.
All the males one month of age and up from the tribe of Levi were counted. Their total was 22,000 (3:39). Then all the firstborn males one month of age and up from the rest of the Israelites were counted. Their total was 22,273 (3:43): the differential between the two figures is 273. God declares that because he spared all the Israelite firstborn at the first Passover in Egypt, the firstborn are peculiarly his (3:13). The assumption, of course, is that at one level they too should have died: they were not intrinsically better than the Egyptians who did. They had been protected by the blood of the Passover lamb God had prescribed. Clearly God was not now going to demand the life of all the Israelite firstborn. Instead, he insists that they are all his in a peculiar way — but that he will accept, instead of all the firstborn males of all Israel, all the males of the tribe of Levi. Since the two totals do not exactly coincide, the 273 extra firstborn males from Israel must be redeemed some other way, and so a redemption tax is applied (3:46-48).
There are some lessons to be learned. One of them is intrinsic to the narrative and already noted: the Israelites were not intrinsically superior to the Egyptians, not intrinsically exempt from the wrath of the destroying angel. More importantly, those saved by the blood belong to the Lord in some peculiar way. If God has accepted the blood that was shed in their place, he does not demand that they die: he demands that they live for him and his service. Owing to the covenantal requirements of the Sinai code, a substitution is accepted: the Levites substitute for all the Israelites who should have come under the sweep of the Passover requirement.
The fulfillment of these patterns under the terms of the new covenant is not hard to find. We are saved from death by the death of the supreme Passover Lamb (1 Cor. 5:7). Those saved by his blood belong to the Lord in a peculiar way, i.e., not only by virtue of creation but by virtue of redemption (1 Cor. 6:20). He demands that we live for him and his service, and in this we constitute a nation of priests (1 Peter 2:5-6; Rev. 1:6).
Numbers 3; Psalm 37; Song of Songs 1; Hebrews 1