Upvote:0
I think there are two senses in which God directly "purchased" Israel at that time:
The first is that as slaves Israel was the property of Egypt. God "purchased" them with the iron price, and throughout the rest of the OT God reminds them that they belong completely and only to him. (I wonder if a concept like the iron price existed in ANE culture. If anyone knows, please comment below!)
The second is that in his saving of the firstborn sons during the passover, the firstborns of Israel effectively owed their lives to God. The firstborns of their sheep and cattle would forever belong to God. Similarly the firstborn human sons were to be consecrated to God (Ex 13), while the Levites would later take their place (Num 3). So God "purchased" the lives of the firstborn sons of Israel when he provided the passover plan to them.
These are both metaphorical senses of purchasing, just as the NT blood of Jesus is. Everything is God's, so I don't think we're ever to understand this language as implying an actual exchange on God's part. But as metaphors they can communicate effectively with us.
Upvote:2
Covenant Theology is the framework of understanding Scripture through the lens of covenants. The Redemption Covenant being the primary oldest one and fulfilled in Christ Jesus. The other two are works and grace.
So, with that in mind, we know the reality that Christ purchased His people with His blood.
In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace; Eph 1:7
Take heed therefore unto yourselves, and to all the flock, over the which the Holy Ghost hath made you overseers, to feed the church of God, which he hath purchased with his own blood. Acts 20:28
In turn, we find one shadow of this in the Abraham and Isaac and ram substitute sacrifice.
But to the OP, we find the primary purchase to which Moses mentions in the form of the Passover lamb. The blood of the lamb purchased the redemption of the people who believed.
In this sense, the nine other plagues of Egypt would also serve as lessons to some to believe God when He spoke about the 10th plague (the death of the firstborn, except for the blood of the Passover lamb). That is the purchase price.
And the blood shall be to you for a token upon the houses where ye are: and when I see the blood, I will pass over you, and the plague shall not be upon you to destroy you, when I smite the land of Egypt. Exo 12:13
In the Song of Moses, Moses is speaking about the crossing through the sea, but as a confirmation of the aforementioned purchase to actually arrive there. First there's the purchase and then the deliverance.
Fear and dread shall fall upon them; by the greatness of thine arm they shall be as still as a stone; till thy people pass over, O LORD, till the people pass over, which thou hast purchased. Exo 15:16
Those purchased via the lamb's blood passed through the sea, while the chasers, the unredeemed, the unpurchased were swallowed by the earth.
Powerful imagery as a foreshadowing of Christ our Passover Lamb.
Forasmuch as ye know that ye were not redeemed with corruptible things, as silver and gold, from your vain conversation received by tradition from your fathers; But with the precious blood of Christ, as of a lamb without blemish and without spot: 1 Pet 1:18-19