Job 40:9

Therefore, the Lord, in accusing Job, proposes the excellence of God over men, and this excellence is indeed manifested in his effects. But since now it is a question of the comparison of justice which properly is not perceived in irrational things, to show divine …

Hast thou an arm like God, and dost thou thunder with a voice like Him? 6. Because blessed Job transcended in merits the race of men, his merciful Creator and Teacher challenges him to consider the resemblance of His greatness, in order that, having known the great dissimilarity, he may keep himself down in humility. 7. But when a voice and arm are spoken of in God, we must take the greatest care that our mind imagines nothing corporeal in Him. For to confine Him within the lineaments of a body, Who without circumscription fills and embraces all things, is to fall into the heresy of the Anthropomorphites. But Almighty God, in drawing us to His own things, humbles Himself even to ours, and, to teach lofty, condescends to lowly things; in order that the mind of little ones, being nourished with the things it knows, may rise to enquire into those it knows not, and hearing from Him Who is far above it, some truths nigh itself, may move, as it were, some steps towards Him. Whence it happens, that in His own Scripture He sometimes from the bodies of men, sometimes from their minds, but sometimes from birds, and sometimes even from insensate objects, applies to Himself some very unlikely resemblances. For He frequently applies to Himself a resemblance from the bodies of men, as the Prophet says of Him to the Israelites, He that hath touched you, toucheth the apple of His eye. [Zech. 2, 8] And as it is said again of Him by the Prophet to a man who trusts in Him; He will make a shadow for thee with His shoulders. [Ps. 91, 4] It is doubtless admitted that God in His own nature has neither eye, nor shoulders; but since we see with our eye, but support burdens on our shoulders, God, because He sees all things, is said to have an eye; but because He carries us, and by carrying preserves us, He is said to make a shadow for us with His shoulders. […]

Hast thou an arm like God?....

"Hast thou, a poor weak worm of the earth, an arm comparable to his who upholds all things?" The power of creatures, even of angels themselves, is derived from God, limited by him, and dependent on him; but the power of God is original, independent, and unlimited.

Hast thou an arm like God? - The arm is the symbol of strength. The question here is, whether Job would venture to compare his strength with the omnipotence of God? Or canst thou thunder with a voice like him? - Thunder is a symbol of the majesty of the Most High, and is often spoken of as the voice of God; see Psa 29:1-11. The question here is, whether Job could presume to compare himself with the Almighty, whose voice was the thunder?