Jeremias 19:5

5 and built high places for Baal, to burn their children in the fire, which things I commanded not, neither did I design in my heart:

Jeremias 19:5 Meaning and Commentary

Jeremiah 19:5

They have also built the high places of Baal
Or, they have even built and so the words explain what is before suggested of their idolatry; these were the temples in which they placed his image, and the altars on which they sacrificed to him; as follows: to burn their sons with fire, [for] burnt offerings unto Baal;
the same idol that is sometimes called Moloch, the names being much of the same signification; the one signifying a "lord" or "master"; the other a king; and to the idol under each name they burned their children with fire, and offered them as burnt offerings unto it; which was a most cruel and barbarous way of sacrificing. Some think they only caused them to pass through two fires; but the text is express for it, that they burnt them with fire, and made burnt offerings of them, as they did with slain beasts. It seems very likely that they did both: which I commanded not;
in my law, as the Targum adds; and which was intimation enough to avoid it; though this was not all, he expressly forbad it, ( Leviticus 20:2-5 ) ; nor spake [it], neither came [it] into my mind;
and it is marvellous it should ever enter into the heart of man; none but Satan himself could ever have devised such a way of worship.

Jeremias 19:5 In-Context

3 and thou shalt say to them, Hear ye the word of the Lord, ye kings of Juda, and men of Juda, and the dwellers in Jerusalem, and they that enter in by these gates; thus saith the Lord God of Israel; Behold, I bring evil upon this place, so that the ears of every one that hears it shall tingle.
4 Because they forsook me, and profaned this place, and burnt incense in it to strange gods, which they and their fathers knew not; and the kings of Juda have filled this place with innocent blood,
5 and built high places for Baal, to burn their children in the fire, which things I commanded not, neither did I design in my heart:
6 Therefore, behold, the days come, saith the Lord, when this place shall no more be called, The fall and burial-place of the son of Ennom, but, The burial-place of slaughter.
7 And I will destroy the counsel of Juda and the counsel of Jerusalem in this place; and I will cast them down with the sword before their enemies, and by the hands of them that seek their lives: and I will give their dead bodies for food to the birds of the sky and to the wild beasts of the earth.

The Brenton translation of the Septuagint is in the public domain.