1020 B
They have turned to the iniquities of their earliest ancestors
The phrase "turned to" is an idiom that means to start doing something. Alternate translation: "They have returned to committing the same iniquities as their earliest ancestors committed" (See: rc://en/ta/man/translate/figs-activepassive)
walked after
"followed after"
The 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 "The kingdom of Israel" (See: rc://en/ta/man/translate/figs-metonymy)
the house of Judah
The word "house" is a metonym for the family that lives in the house. In this case it refers to the kingdom of Judah, which included the descendants of Judah and Benjamin. See how you translated this in Jeremiah 3:18. Alternate translation: "Judah" or "the kingdom of Judah" (See: rc://en/ta/man/translate/figs-metonymy)