1 Kings 7:46

In the plain of Jordan did the king cast them—Zarthan, or Zaretan (Joshua 3:16), or Zartanah (I Kings 4:12), or Zeredathah (II Chronicles 4:17), was on the bank of the Jordan in the territories of western Manasseh. Succoth was situated on the eastern side of Jordan, at the ford of the river near the mouth of the Jabbok. One reason assigned by commentators for the castings being made there is, that at such a distance from Jerusalem that city would not be annoyed by the smoke and noxious vapors necessarily occasioned by the process. [Note in Bagster's Bible.] But the true reason is to be found in the nature of the soil; Margin, "the thickness of the ground." That part of the Jordan valley abounds with marl. Clay and sand are the moulding material still used for bronze. Such large quantities of metal as one of these castings would contain could not be fused in one furnace, but would require a series of furnaces, especially for such a casting as the brazen sea—the whole series of furnaces being filled with metal, and fused at one time, and all tapped together, and the metal let run into the mould. Thus a national foundry was erected in the plain of Jordan [NAPIER].