RobH_en_tn/jer/03/20.md

But like a woman faithless to her husband, you have betrayed me

God speaks of Israel being unfaithful to him as if she were an unfaithful wife. (See: rc://en/ta/man/translate/figs-simile)

house of Israel

The word "house" is a metonym for the family that lives in the house. In this case it refers to the kingdom of Israel. See how you translated this in Jeremiah 3:18. Alternate translation: "Israel" or "kingdom of Israel" or "people of Israel" (See: rc://en/ta/man/translate/figs-metonymy)

this is Yahweh's declaration

Yahweh speaks of himself by name to express the certainty of what he is declaring. See how you translated this in Jeremiah 1:8. Alternate translation: "this is what Yahweh has declared" or "this is what I, Yahweh, have declared" (See: rc://en/ta/man/translate/figs-123person)