Charles Ellicott Commentary Job 2:12

"And when they lifted up their eyes afar off, and knew him not, they lifted up their voice, and wept; and they rent every one his robe, and sprinkled dust upon their heads toward heaven." — Job 2:12 (ASV)

And knew him not. —Compare the converse statement descriptive of the love of him who could recognize his lost son under a disguise as great as that of Job, or even greater (Luke 15:20).