Isaiah43chapter 43

The ransom language is commercial. God says he gave Egypt for Israel's ransom, and Cush and Seba in exchange. That is the language of a redemption price paid to buy back a person sold into slavery — and in the century after Isaiah spoke, Assyria did in fact conquer Egypt and Cush, which readers would come to see as the price being handed over.

The old rescue is retold in one line of imagery: the LORD who makes a way in the sea and a path in the mighty waters, who brings out the chariot and horse, the army and the power, and they lie down together and do not rise, quenched like a wick. That is the Red Sea seen from the far bank.

Then the surprising instruction: do not remember the former things, or consider the things of old. For a people whose entire faith ran on remembering the Exodus, that is nearly shocking. The reason follows — behold, I do a new thing, now it springs forth, and I will make a road in the wilderness and rivers in the desert. The first exodus was through water and out of it. The second is through desert, with water added.

The animals in that desert are named as worshippers, which is an unusual touch: the wild beasts will honor me, the jackals and the ostriches, because I give waters in the wilderness to give drink to my people.

The complaint at the end is an accountant's complaint about the sacrificial system, and it is worth knowing what each item cost. You have not brought me the lamb of your burnt offerings, and you have not honored me with your sacrifices — and then, you have bought me no sweet cane with money. Aromatic cane was an imported ingredient of the holy anointing oil, and it had to be paid for. God says he never wore them out with demands for grain offerings or incense; what they gave him instead was their sins.