arm (zeroa`, 'ezroa`, dera`; brachion; chotsen, katheph): The usual form is zeroa` from the root zara`, "to spread." The arm may be "stretched out." 'Ezroa` is this form with prosthetic 'aleph (Job 31:22; Jer 32:21), and dera` is the Aramaic form. Chotsen is really "bosom," thus the Revised Version (British and American) (Isa 49:22); and katheph is "shoulder," thus the Revised Version (British and American) (Job 31:22). Compare cheir, also, in Ac 11:21.
Figurative: The arm denotes influence, power, means of support or conquest. The arms of Moab (Jer 48:25) and of Pharaoh (Eze 30:21 ff) are broken. The arm of Eli and the arm of his father's house are to be cut off (1Sa 2:31). Because the arm wielded the sword it signified "oppression" (Job 35:9). The arms are the means of support, therefore to refuse to aid the fatherless is to break their arms (Job 22:9).
Applied anthropomorphically to God, the arm denotes also His power, power to deliver, support, conquer. His "outstretched arm" delivered Israel from Egypt (Ex 6:6; De 4:34, etc.). They support: "Underneath are the everlasting arms" (De 33:27). His arm protects (Isa 40:11). Yahweh is sometimes likened to a warrior and smites with His arm (Ps 89:10; Isa 63:5; Jer 21:5). The arm of Yahweh is holy (Ps 98:1; Isa 52:10). Many other passages of Scripture might be quoted showing how the power of God to redeem, judge, protect, punish is expressed by the idea of "the arm of Yahweh."
S. F. Hunter