9:15 What the Israelites did at Gilgal caused the Lord to hate them. This is covenant terminology meaning He opposed them; personal emotion is not in view. At Gilgal the Israelites practiced the pagan fertility cult (cf. 4:15; 12:11). Yahweh would drive His people out of the land, as He had expelled Adam and Eve and the Canaanites, because they had sinned and had adopted the ways of sinners. He would love (choose to bless) them no more, as He had in the past, because all their leaders rebelled against Him.
Even though God loves (chooses) all the elect (Eph. 1:4), He has a special affection for those who comply with His will (cf. John 15:14). The Israelites had stopped being compliant and had been rebellious.
9:16 The Lord had stricken the very roots of the nation so it would dry up and bear no fruit (cf. Mal. 4:1). This probably refers to human barrenness, agricultural unfruitfulness, and animal infertility. Even though the people bore children that were precious to them, the Lord would slay them.
9:17 Hosea's God would cast the Ephraimites out of the land because they proved unresponsive to Him. They would end up wandering among the other nations of the world. Because they had wandered from the Lord, they would wander in the earth, like Cain whom the Lord also cursed (cf. Gen. 4:12).
