at.tun denotes the heated fire enclosure into which people are threatened, cast, and from which they emerge.

The term consistently denotes the fire enclosure in Daniel 3: it is named as the place of threatened punishment, intensified heating, confinement, and the place from which the three men come out.

1. The heated fire enclosure · dominant

   Across the chapter, the construct singular form identifies the place into whose midst people are to be cast or fall; in Daniel 3:6 the APB renders the clause "cast into the midst of a burning fiery furnace," and Daniel 3:23 describes the three men falling bound into that midst. The same enclosure is heated in Daniel 3:19 and Daniel 3:22, and in Daniel 3:26 it has a door from which the men are summoned to come out.

   Daniel 3:6Daniel 3:19Daniel 3:22Daniel 3:23Daniel 3:26

In the Anselm Project Bible: The APB consistently presents the setting as a "burning fiery furnace," while Daniel 3:19 and Daniel 3:22 use "the furnace" in clauses about heating it. These renderings describe the verse context rather than providing word-by-word alignment.