And one polluted them in their own gifts,.... Suffered them to defile themselves; or declared them to be, and treated them as polluted persons, in the gifts and sacrifices which they offered to idols, particularly their firstborn: as the next clause explains it:in that they caused to pass though [the fire] all that openeth the womb; this very likely they did, when they sacrificed to Baalpeor, the same with Molech, Nu 25:3;that I might make them desolate; their families, by stripping them of their children, their firstborn, and strength:to the end that they might know that I [am] the Lord; a righteous God, in punishing men for sin, in a way it deserves.
Some interpret this, not of causing the firstborn to pass through fire to an idol; but of causing them to pass, or of setting them apart, to the Lord, according to the law in Ex 13:12; where the same word is used as here; and the sense is that God declared them to be impure in or with all their gifts, by commanding them to cause their firstborn to pass to him, which they were obliged to redeem; which sense is approved of by Gussetius ; and so Abendana, taking the words to refer to both, gives this sense of them,"I pronounced them impure, and removed them far from me, instead of sanctifying them; because they caused everyone that opens the womb to pass from me, whom I commanded to give to me for holiness, but they have given them to idolatry;''rather, according to Braunius , the words may be understood of God's rejecting and causing the firstborn to pass from him, and not suffering them to offer gifts and sacrifices unto him; which may be meant by pronouncing them impure, or polluting them in their gifts; this was after the worship of the golden calf; when he took Aaron and his sons in their room.
Ebr. Comment. p. 576, 939. Selecta Sacra, l. 4. c. 11. p.