The word אֲנָךְ, anak, occurs only in this vision — twice in verse 7 and twice in verse 8 — and nowhere else in the Hebrew Bible. The gloss reads tin, and the reading line follows it.

Most English versions read plumb line instead, and have since the King James. That rendering rests on the assumption that anak meant lead: lead weights a builder’s line, so a lead word became a line word by association. But Hebrew already has a word for lead — עֹפֶרֶת, oferet — and the Akkadian cognate annaku, identified once Akkadian could be read, is tin rather than lead. Landsberger set this out in 1965; the lexicons have been slow to follow, and the older entry is still what most translations are working from.

The ancient versions did not see a plumb line either, and no two of them saw the same thing. The Septuagint reads adamas, an adamant or hard metal, and the Syriac agrees. The Vulgate has trulla caementarii, a mason’s trowel, with the wall plastered rather than metal. Aquila read brightening; Theodotion, something melting. The Targum set the metaphor aside altogether and rendered the wall a place of judgment, with judgment against Israel in the hand. The plumb line itself enters late, through medieval grammarians — Rashi and Ibn Ezra both noted an Arabic sense of lead or tin, and the line was inferred from the lead.

What the vision holds is a wall of soft metal and a piece of the same metal in the hand. Whether that is a standard held up against a crooked wall, or something else, the text does not say.