Albert Barnes Commentary Job 19:8

"He hath walled up my way that I cannot pass, And hath set darkness in my paths." — Job 19:8 (ASV)

He has fenced up my way — This figure is taken from a traveler whose way is obstructed by trees, rocks, or fences, so that he cannot get along. Job says it was so with him. He was traveling along in a peaceful manner on the journey of life, and all at once obstructions were put in his path, so that he could not go farther. This does not refer, particularly, to his spiritual condition, if it does at all. It is descriptive of the obstruction of his plans, rather than of spiritual darkness or distress.

And he has set darkness in my paths — So that I cannot see — as if all around the traveler should become suddenly dark, so that he could not discern his way. The language here would well express the spiritual darkness which the friends of God sometimes experience, though it is by no means certain that Job referred to that. All the dealings of God are to them mysterious, and there is no light in the soul — and they are ready to sink down in despair.