Deuteronomy 4:20

But the Lord hath taken you, and brought you forth out of the iron furnace ,.... The allusion is to the trying and melting of metals, and fleeing them from dross, by putting them into furnaces strongly heated, some of which are of earth, others of iron; the word, as the Jewish writers F7 Maimon. & Bartenora in Misn. Celim. c. 8. sect. 9. & Jarchi in loc. observe, signifies such an one in which gold and silver and other things are melted; see Psalm 12:6 even "out of Egypt"; which is here compared to an iron furnace, because of the cruelty with which the Israelites were used in it, the hardships they were put under, and the misery and bondage they were kept in; but out of all the Lord brought them, as he does all his people sooner or later out of their afflictions, sometimes called the furnace of affliction, Isaiah 48:10 where their graces are tried, and they are purged, purified, and refined from their dross and tin. This the Lord did to Israel, he brought them out of their distressed state and condition:

to be unto him a people of inheritance, as ye are this day : to be the Lord's inheritance, as they now were, Deuteronomy 32:9 as well as they were quickly to inherit the land of Canaan, for which they were brought out of the land of Egypt; and indeed they were already, even that day, entered on their inheritance, the kingdom of the Amorites being delivered into their hands.