Adam Clarke on Jeremiah 3:19

How shalt I put thee among the children - As if he had said, How can ye be accounted a holy seed, who are polluted? How can ye be united to the people of God, who walk in the path of sinners? How can ye be taken to heaven, who are unholy within, and unrighteous without?

And I said, Thou shalt call me, My father - This is the answer to the above question. They could not be put among the children unless they became legal members of the heavenly family: and they could not become members of this family unless they abandoned idolatry, and took the Lord for their portion. Nor could they be continued in the privileges of the heavenly family, unless they no more turned away from their heavenly Father.