Why does it say that Hashem planted you?
Radak: Yisrael are compared to an olive-tree, so an expression of planting applies. He made you dwell in a good land, just like He benefited you when you did good. So now He spoke about you through the Nevi'im that in the future will come upon you due to the evil of Beis Yisrael and Beis Yehudah. For Beis Yisrael, He spoke evil and it came upon them. Also on you (Beis Yehudah), He spoke evil and it will come upon you.
Malbim: He did not change His mind. He spoke about you evil because He planted you! The planting was in order that you will make Kadosh fruits of praise [to Hashem]; you made fruits of death and bereavement. A gardener will uproot a tree that he planted if he sees that it makes spoilage.
What is the meaning of "Asu Lahem Lehach'iseni Lekater la'Ba'al"?
Malbim: Initially they did evil for their pleasure. Later they did to anger Me. Afterwards they offered to Ba'al, and afterwards they clung to it and believed in it.
