The Shamir

A creature the size of a barleycorn that cuts any stone, iron or diamond simply by being passed over it. Listed in Avot 5:6 among the ten things created at twilight on the eve of the first Sabbath — the tradition's category for objects that are neither miracle nor nature but were built into the world at the seam. It could not be kept in any container it would cut through, so it was wrapped in wool inside a lead tube, packed in barley bran (Sotah 48b).

Solomon needed it to build the Temple, since iron tools were forbidden on the stones, and the Talmud's account of how he obtained it (Gittin 68a–b) is a long, strange, very funny story involving the binding of a demon king. ⚠ Reference only. This app describes that narrative; it hands you nothing to do with it.

Look at what the thing is, though: the Temple's one permitted cutting tool is not a tool at all. It is an animal, and it works by the same organ Isaiah's worm does. The house of the Name had to be cut by a mouth.