Albert Barnes Commentary Jeremiah 8:5

"Why then is this people of Jerusalem slidden back by a perpetual backsliding? they hold fast deceit, they refuse to return." — Jeremiah 8:5 (ASV)

When people act as described in Jeremiah 8:4, why are God’s own people alone an exception?

Slidden back ... backsliding – These are the same words as “turn” and “return” in Jeremiah 8:4. They should be rendered, “Why does this people of Jerusalem turn away with a perpetual turning?”

Deceit – that is, idolatry; because in it, people worship what is false, and it proves false to its worshippers.

Refuse – From a feeling of dislike.