Charles Ellicott Commentary Jeremiah 17:2

"whilst their children remember their altars and their Asherim by the green trees upon the high hills." — Jeremiah 17:2 (ASV)

While their children remember ... —If we take “children” as referring to age, there may be a reference to the way in which the horrors of Molech worship were seared into the minds of boys who were present at such a spectacle, so as never to be forgotten, but the general sense in which we speak of the “children” of Israel or Judah seems sufficient. The thought expressed is that every locality that could be used for idolatrous worship made them “remember” that worship, and begin to reproduce it. By some interpreters, the clause is interpreted, as they remember their children, so they also remember their altars and their groves; that is, their idols are as dear to them as their offspring. The former interpretation is, however, the more natural, and is best supported by the versions.

Groves. — i.e., as throughout the Old Testament, when connected with idolatry, the wooden columns that were the symbols of the Phoenician goddess Asherah, possibly the same as Astarte (Exodus 34:13; Deuteronomy 16:21; 1 Kings 14:23). The “green trees” suggested the thought of this worship—for the Asherah, though not a grove, was generally connected with one—as the “high hills” did that of the altars. Commonly the worship is described as “under every green tree.” Here a different preposition is used, “on the green trees,” connecting them with the verb “remember.”