The account of the LORD’s descent on to Mount Sinai in Exodus 19 is full of surprises. Moses alone is permitted to go up to the LORD, and God firmly instructs him to ‘“Go down and warn the people so they do not force their way through to see the LORD and many of them perish”’ (Exodus 19:21 NIV). The real surprise is found in the next verse where God states: ‘“Even the priests, who approach the LORD, must consecrate themselves, or the LORD will break out against them” (Exodus 19:22 NIV). It is surprising for the simple reason that at this point in the history of Israel the Levitical priesthood did not yet exist, and the reader of the passage is left asking the question, who were the priests introduced in this verse? A similar warning concerning who could approach God is repeated in verse twenty four; the LORD’s desire for Aaron to ascend Sinai with Moses perhaps pre-empts the eclipsing of the old and beginning of a new, yet to be divulged, priestly order: ‘The LORD replied, “Go down and bring Aaron up with you. But the priests and the people must not force their way through to come up to the LORD, or he will break out against them”’.

The answer to the puzzle of the priests’ identity is not explained until Exodus 22:29 where the LORD, in the giving of the law to Moses, says ‘“You must give me the firstborn of your sons”’ תִּתֶּן־לִּי בָּנֶיךָ בְּכוֹר (beḵor baneḵa titen li lit. your firstborn sons are a gift to me). At this point no explanation is given as to what such an offering entails, but in the context of the first half of the verse which declares ‘Do not hold back offerings from your granaries or your vat’ it is perhaps to be inferred that the sons are to be presented as a sacrifice. The verse following similarly states: ‘Do the same with your cattle and your sheep. Let them stay with their mothers for seven days, but give them to me on the eighth day’. Certainly, the practice of sacrificing animals had already become part of the clan culture of the Hebrews and the ram that Abraham offers to God in Genesis 22 is described as a burnt offering, לְעֹלָה (leolah). Of course, in the same story Isaac is offered up as a sacrifice, but God speaks from heaven making it clear that he does not want the boy’s life – when it comes to human beings the LORD implicitly forbids the Israelites from following in the ways of the Canaanites who were known to practise child sacrifice. Like Isaac, it seems, the firstborn sons of Israel were then, to be ‘living sacrifices’, set apart for lifetime service to God. Indeed, the word for ‘priest’ in the Hebrew Bible is כֹּהֵן (kohen, plural kohanim כֹּהֲנִים) and its meaning, although debated, may just mean ‘servant’. Moreover, the idea of the priest being the one set apart for service is in fact confirmed in Numbers 3 where Yahweh once against speaks to Moses:

‘The Lord also said to Moses, “I have taken the Levites from among the Israelites in place of the first male offspring of every Israelite woman. The Levites are mine, for all the firstborn are mine. When I struck down all the firstborn in Egypt, I set apart for myself every firstborn in Israel, whether human or animal. They are to be mine. I am the LORD.”’ (Numbers 3:11-13 NIV)

There is no longer any mystery or ambiguity, the priests of Exodus 19:22,24 are the firstborn in Israel. However, the book of Numbers reveals that God has decided that the firstborn sons are not to continue in this role, but that the tribe of Levi should be set apart to fulfil the priestly office. In fact, the scope of God’s intentions towards his people in relation to the priesthood may go further than the Levitical tribe - at Moses’ first encounter with God on Mount Sinai, God had instructed him to tell the Israelites that: ‘out of all nations you will be my treasured possession. Although the whole earth is mine, you will be for me a kingdom of priests and a holy nation’ (Exodus 19:5-6 NIV). The implication is perhaps, that Israel will be the firstborn among the nations, and indeed back in Exodus 4 Moses is told to say to Pharaoh: ‘Then say to Pharaoh, ‘This is what the LORD says: Israel is my firstborn son, and I told you, “Let my son go, so he may worship me.” But you refused to let him go; so I will kill your firstborn son’” (Exodus 4:22-23 NIV). The commissioning of the Levites then, to serve as priests, may just be a temporary one, to be relinquished when the time comes to release all Israel into his promised priestly role.

The motif of the firstborn is of course picked up by the New Testament writings of Paul and in Colossians 1:15 he writes, ‘The Son is the image of the invisible God, the firstborn over all creation’. In its wider literary context then, such a statement is more than just relating to the raising of Christ from the dead; the verse casts Jesus as the new Adam, but even more than that, as the firstborn of a new Israel, the firstfruits of a new creation. Such an interpretation helps solve the difficult theological conundrum of Jesus’ identity as a kohen. The priesthood originally belonged to all the firstborn and had only been entrusted to Levi. John’s baptism of Jesus is a vivid symbol of the transference of the priestly office to Jesus. Indeed, the miraculous escape of the firstborn of Israel from Egypt, along with the miraculous birth of Isaac seem to prefigure the coming of a kohen, who would be a firstborn son, born of miraculous means, who would live his life as servant, and be the ultimate expression of what it means to be a living sacrifice.