Job 31:22

Then let mine arm fall from my shoulder blade, and mine arm be broken from the bone.

Job's oath is solemn and conditional, calling for his own arm to fall from its shoulder blade and shoulder socket and to be broken from the bone if guilt is found in him. It is a self-invoked physical punishment, a willingness to have the arm torn from its place and shattered as judgment upon himself. The oath belongs to his defense of his conduct, not to any general promise about suffering.

Its stated condition is abuse of the powerless, specifically keeping food back from the fatherless, leaving the poor without clothing or covering, and lifting the hand against or harming the fatherless. If he had done so, he consented to suffer loss of the arm and its breaking as the consequence. The oath is therefore part of his appeal to divine judgment, affirming with confidence that he has kept his moral character unstained and has cared for those in need.

It stands within his wider testimony that he did not trust in riches nor rejoice because wealth was great, but regarded his possessions only as a means to bless the poor, the needy, the fatherless, and the widow. He trusted in the living God who gives power to get wealth, for being rich is not sin, while trusting in riches, putting confidence in them, rejoicing in them, and becoming proud and high-minded because of them denies the God who is above. In this way care for the needy is set forth as a matter of serious moral accountability.

The chapter as a whole is his protestation of integrity, showing that true honesty is more than paying all debts to fellow men and owing no one anything. True honesty means integrity, justice, frankness, chasteness, candor and dazzling whiteness, and it includes reckoning indebtedness to God for everything received, not freedom from liability to fellow men alone. Yet recounting these good deeds in self-defense led him to rely on his own works instead of giving God the glory, when the blessings and the very ability to help others came from God and were meant to be passed on.