his heart had turned away from him

The words "his heart had turned" refer to his having changed allegiance and affection. See how you translated a similar phrase in 1 Kings 11:1. Alternate translation: "Solomon had stopped worshiping Yahweh" (See: rc://en/ta/man/translate/figs-idiom and rc://en/ta/man/translate/figs-metonymy)

he had appeared to him twice

"Yahweh had appeared to Solomon twice"