▼ The term “ax head” does not appear in the Hebrew text, but is supplied in the translation for clarity. The preceding noun “iron” functions as a metonymy of material (i.e., iron) for the object with which it is associated (i.e., ax head).

▼ Heb “he”; the referent (the workman) is implied, and has been specified in the translation for clarity

▼ The verb קלל in the Pilpel means “to sharpen; to make a blade sharp” (HALOT 1104 s.v. קלל 1).This denominative verb is derived from the rare noun II קָלַל “smooth; shiny” (referring to bronze; Ezek 1:7; Dan 10:6; HALOT 1105 s.v.). Sharpening the blade or head of a bronze ax will make it smooth and shiny. It is not derived from I קָלַל (qalal) “to treat light” or the noun I קְלָלָה (q^elalah) “curse.” Nor is it related to I קָלַל “to shake” (Ezek 21:26); cf. HALOT 1104. BDB 886 s.v. קָלַל 2 erroneously relates it to I קָלַל, suggesting “to whet” or “to move quickly to and fro.”

▼ Heb “face.”

▼ Heb “strength.” The term וַחֲיָלִים (vakhayalim, conjunction + plural noun from חַיִל, khayil, “strength; efficiency”) is an example of a plural of intensification (GKC 397–98 #124.e). The point is that it is a waste of a great deal of strength and energy. If a person is not smart, he will have to use a lot of energy and waste his efficiency.