In weaving, the group of threads running the length of the fabric. The set of threads woven alternately over and under these at right angles across the cloth constitutes the woof. When Israel’s priests tested woven materials for leprosy, they inspected both the warp and the woof.​—Le 13:47-59; see LEPROSY (In garments and houses); WEAVING.

Upon completing the cloth, the weaver cuts across the warp threads, removing the material and leaving the “thrums,” or ends of the warp threads, fastened to the loom. King Hezekiah alluded to this in recalling his severe illness when he thought that God was about to cut short his life, cutting Hezekiah off “from the very threads of the warp” in untimely death.​—Isa 38:9-12.