Job 31:22

“[Then] let mine arm fall from my shoulder blade, etc.] With which the upper part of it is connected; let it be disjointed from it, or rot and drop off from it; a dreadful calamity this, to lose an arm and the use of it, to have it full off immediately, as a judgment from God, and in just retaliation for lifting up an hand or arm against the fatherless; as Jeroboam’s arm withered when he put it forth from the altar, and ordered hands to be laid upon the prophet for crying against the altar, (<111304>1 Kings 13:4); and mine arm be broken from the bone; from the channel bone, as the margin of our Bibles, or rather from the elbow, the lower part of the arm and so may be rendered, “or mine arm”,…”

“Apodosis to Job 31:13, Job 31:16-17, Job 31:19-21. If I had done those crimes, I should have made a bad use of my influence ("my arm," figuratively, Job 31:21): therefore, if I have done them let my arm (literally) suffer. Job alludes to Eliphaz' charge (Job 22:9). The first "arm" is rather the shoulder. The second "arm" is the forearm. from the bone--literally, "a reed"; hence the upper arm, above the elbow.”

“Then let mine arm - The strong language which Job uses here, shows his consciousness of innocence, and his detestation of the offences to which he here refers, Job 31:16-22. The word rendered “arm” here (כתף kâthêph) means properly the shoulder. Isaiah 46:7; Isaiah 49:22; Numbers 7:9; compare the notes at Isaiah 11:14. There is no instance, it is believed, unless this is one, in which it means arm, and the meaning here is, that he wished, if he had been guilty, his shoulder might separate from the blade. So Herder, Rosenmuller, Umbreit, and Noyes render it; and so the Vulgate and the Septuagint. From my shoulder-blade - The scapula - the flat bone to which the upper arm is attached. The…”

“31:22-23 If an arm was used in sinful action (31:21), having it torn from its socket would be a fitting punishment and better than facing God’s judgment (cp. Matt 5:28-30).”

“let: Job 31:10, Job 31:40; Jos 22:22, Jos 22:23; Psa 7:4, Psa 7:5, Psa 137:6 bone: or, chanel bone Job 31:23”