Albert Barnes Commentary Ezekiel 16:20-21

"Moreover thou hast taken thy sons and thy daughters, whom thou hast borne unto me, and these hast thou sacrificed unto them to be devoured. Were thy whoredoms a small matter, that thou hast slain my children, and delivered them up, in causing them to pass through [the fire] unto them?" — Ezekiel 16:20-21 (ASV)

Borne unto me - me is emphatic. The children of Yahweh have been devoted to Moloch. The rites of Moloch were twofold:

1. The actual sacrifice of men and children as expiatory sacrifices to false gods.
2. The passing of them through the fire by way of purification and dedication.

Probably the first is alluded to in Ezekiel 16:20; the two rites together in Ezekiel 16:21.