'Arm' in the Bible

Therefore say to the sons of Israel, I am Jehovah, and I have brought you out from under the burdens of the Egyptians, and have delivered you from their service, and have redeemed you by a stretched-out arm, and by great judgments,

Fall on them doth terror and dread; By the greatness of Thine arm They are still as a stone, Till Thy people pass over, O Jehovah; Till the people pass over Whom Thou hast purchased.