Albert Barnes 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 their altars - Perhaps an allusion to their sacrifices of children to Moloch. Present, perhaps, at such a blood-stained rite, its horrors would be engraved forever on their memory.

Groves - “Asherahs,” that is, wooden images of Astarte (see Exodus 34:13 note).