This verse is part of a longer passage in the Wisdom of Solomon (13:10-19) that critiques the folly of idolatry. Here's a breakdown of the verse and its meaning in context:

"And having made for it a chamber worthy of it...": This refers to a craftsman creating a special, often ornate, housing or shrine for the idol they have carved. The emphasis is on the effort and expense put into the idol's dwelling place. They are treating an inanimate object as if it deserves the finest accommodation.

"He sets it in a wall...": This suggests the idol is being placed in a prominent, visible location within a building or structure. It's being given a position of honor and importance.

"...making it fast with iron.": The idol is secured in place, often with iron fastenings, to prevent it from falling, being stolen, or being seen as insignificant. This highlights the lengths to which people go to protect and preserve their idols.

Overall Meaning:

The verse satirically describes the absurdity of idolatry. People lavish care and attention on idols, constructing elaborate shrines and securing them with iron. This action implies that the creator is investing time, energy, and resources into something entirely powerless and inanimate. The passage underscores the irrationality of worshipping something made by human hands, contrasting it with the worship of the true, living God.

Contextual Significance:

The Wisdom of Solomon uses this detailed description to argue that:

Idolatry is foolish: It's an act of irrationality to worship something that is merely a product of human craft.
God is the true source of all things: The passage implies that people should direct their worship toward the one who created the world, not toward lifeless images.
Idols are powerless: Despite all the effort put into housing and securing them, idols are ultimately incapable of helping or protecting their worshippers.

In essence, the verse paints a picture of misplaced devotion and the futility of worshipping creations rather than the Creator.