isaiah 54:16 Behold, I have created the smith that bloweth the coals in the fire, and that bringeth forth an instrument for his work; and I have created the waster to destroy. - Free Bible Online

      16. The workman that forms "weapons against thee" (Isa 54:17) is wholly in My power, therefore thou needest not fear, having Me on thy side.
      for his work--rather, "by his labor [HORSLEY]. "According to the exigencies of his work" [MAURER].
      waster to destroy-- (Isa 10:5-7; 37:26, 27; 45:1-6). Desolating conquerors who use the "instruments" framed by "the smith." The repetition of the "I" implies, however, something in the latter half of the verse contrasted with the former understand it, therefore, thus: "I have in My power both him who frames arms and him who destroys them (arms)" [ROSENMULLER].

JFB.