Charles Ellicott Commentary Isaiah 35:8

"And a highway shall be there, and a way, and it shall be called The way of holiness; the unclean shall not pass over it; but is shall be for [the redeemed]: the wayfaring men, yea fools, shall not err [therein]." — Isaiah 35:8 (ASV)

An highway shall be there. — This refers to the raised causeway, as distinct from the common paths . We are still in the region of parables, but the thought has a special interest as a transition at the close of the first volume of Isaiah’s writings to the opening of the second. Some interpreters have referred the use of the road to the return of the exiles from Babylon. Rather, it is the road by which the pilgrims of all nations shall journey to the mountain of the Lord’s house (Isaiah 2:1).

The way of holiness ... — The name of the road confirms the interpretation just given. There was to be a true Via Sacra to the earthly temple, as the type of that eternal Temple, not made with hands, which was also in the prophet’s thoughts. Along that road, there would be no barbarous invaders polluting the ground they trod, and no Jews who were ceremonially or spiritually unclean. The picture of the heavenly Jerusalem (Revelation 21:27), into which there entereth nothing that defileth, presents a like feature.

It shall be for them, that is . . . It is appointed for those, for whoever walks on it (the Hebrew verb is in the singular). Then, in strict order, comes the final clause: Even the simple ones shall not lose their way. A curious parallel is found in Ecclesiastes 10:15, where he knoweth not how to go to the city, is one of the marks of the man who is void of understanding.