This verse from Jeremiah 6:20, as found in the Book of Baruch (also known as the Letter of Jeremiah), is a powerful critique of idolatry. Let's break it down:

"They are as one of the beams of the temple..." This refers to idols. Like structural beams in a temple, idols are made of wood or stone, inanimate objects. They are presented as strong and important, part of a sacred space.

"...and men say their hearts are eaten out..." This highlights the irony and absurdity of idol worship. People claim these idols have hearts (metaphorically representing life, emotion, or power), but the idols are lifeless objects.

"...when things creeping out of the earth devour both them and their raiment: they feel it not." This is the core of the verse. This describes the vulnerability and powerlessness of the idols. Creeping things (like insects, worms, or other vermin) from the earth are able to eat away at the idols and their clothing without any resistance or reaction.

"...they feel it not." This is the final punchline. The idols cannot feel or react because they are inanimate. They are unable to protect themselves or their surroundings, highlighting their utter lack of power or sentience.

In summary, the verse is a satirical attack on idol worship:

It exposes the ridiculousness of believing in idols by highlighting their complete inability to defend themselves from even the most insignificant creatures. It contrasts the perceived strength and importance of idols with their actual helplessness. The verse essentially argues that if these "gods" can't even protect themselves, they certainly can't protect or help the people who worship them.

The image is meant to be disturbing and thought-provoking, forcing the reader to question the wisdom and rationality of idolatry.