Albert Barnes Commentary Isaiah 42:16

"And I will bring the blind by a way that they know not; in paths that they know not will I lead them; I will make darkness light before them, and crooked places straight. These things will I do, and I will not forsake them." — Isaiah 42:16 (ASV)

And I will lead the blind - Having said in the previous verses what he would do to his enemies, God now speaks of his people. He would conduct them to their own land, as a blind people who needed a guide, and would remove whatever obstacle there was in their way. By the ‘blind’ here, he refers, doubtless, to his own people. The term is applied originally to his people in captivity, as being ignorant, after their seventy years’ exile, of the way to return to their own land. It is possible that it may have a reference to the fact so often charged against them, that they were characteristically a dull and spiritually blind people.

But it is more probable that it is the language of tenderness rather than that of rebuke, and denotes their ignorance of the way to return and their need of a guide, rather than their guilt and hardness of heart. If applied to the people of God under the New Testament—as the entire tone of the prophecy seems to lead us to conclude—then it denotes that Christians will feel their need of a leader, counselor, and guide; and that Yahweh, as a military leader, will conduct them all in a way they did not know, and remove all obstacles from their path.

By a way that they knew not - When they did not know what course to take, or in a path they did not contemplate or design. It is true of all the friends of God that they have been led in a way they did not know. They did not mark out this course for themselves; they did not at first form the plans of life they ultimately came to pursue. They have been led by the providence of God in a different path, and by the Spirit of God they have been inclined to a course they themselves would never have chosen (Compare to the note at Isaiah 30:21).

I will make darkness light before them - Darkness, in the Scriptures, is the emblem of ignorance, sin, adversity, and calamity. Here it seems to be the emblem of adverse and opposing events—of calamities, persecutions, and trials. The meaning is that God would make those events that seemed adverse and calamitous the means of furthering his cause, and promoting the spirit of the true religion and the happiness of his people.

This has been eminently the case with the persecutions the church has endured. The events that have apparently been most adverse have ultimately been overruled for the best interests of the true religion. Such was the case with the persecutions under the Roman emperors, and in general, such has been the case in all the persecutions the church has been called to suffer.

And crooked things straight - Things that seem adverse and opposing—the persecutions and trials the people of God would be called to endure.

And not forsake them - (See the note on Isaiah 41:10 and the note on Isaiah 41:13).