to wall up: to stack stones into a barrier, whether to close a way shut or to close a gap in a wall that has fallen in.
This is the action behind the Hebrew noun for a low stone wall (גָּדֵר): gathering loose field stones and stacking them into a line. It is humble work, not engineering. The picture stays close to the ground, where a farmer closes the edge of a plot or a workman fills the hole left where stones have tumbled out.
The same act reads two opposite ways depending on which side of the wall you stand on.
- Laid across a path, the stones shut a person in, and in every passage of that kind God is the one stacking them.
- Laid across a gap, the stones put a ruin back together, and whoever does it is doing the work of a rescuer.
That is how one word covers both the sufferer in Lamentations who cannot find a way out and the man Ezekiel says God looked for, who would close the gap in the wall and could not be found.
The gap-closing use almost always names the specific hole being filled: the word for a break in a wall (פֶּרֶץ) stands beside it in nearly every case. To be called someone who closes the break, as in Isaiah 58:12, is high praise, and in Amos God promises to do it himself for the fallen shelter of David. The Greek Old Testament rendered that promise with a verb meaning "rebuild" (ἀνοικοδομέω), which is the wording James uses when he quotes Amos in Acts 15:16.
Twice the word simply becomes a job title. In the accounts of repairs to the temple, the wall-builders are listed alongside the carpenters and the stonecutters and paid out of the collection money, exactly as a trade would be.