Albert Barnes Commentary Job 19:6

"Know now that God hath subverted me [in my cause], And hath compassed me with his net." — Job 19:6 (ASV)

Know now that God - Understand the situation; and so that they could, he goes into an extended description of the calamities which God had brought upon him. He wished them to be fully informed of all that he had suffered by God's hand.

hath overthrown me - The word used here (עות ‛ âvath) means to bend, to make crooked or curved; then to distort, pervert; then to overturn, to destroy (Isaiah 24:1; Lamentations 3:9). The meaning here is that he had been in a state of prosperity, but that God had completely reversed everything.

and hath compassed me with his net - Has sprung his net upon me as a hunter does, and I am caught. Perhaps there may be an allusion here to what Bildad said in Job 18:8 and following, that the wicked would be taken in his own snares. Instead of that, Job says that God had sprung the snare upon him—for reasons which he could not understand, but in a manner that should move the compassion of his friends.