Ellicott's Commentary for English Readers - Isaiah 40:5
(5) The glory of the Lord shall be revealed.—Did the prophet think of a vision of a glory-cloud, like the Shechinah which he had seen in the Temple? or had he risen to the thought of the glory of character and will, of holiness and love? (John 1:14.)All flesh.—The revelation is not for Israel only, but for mankind. So in Luke 3:6, the words are quoted from the LXX., “all flesh shall see the salvation of God.” The phrase meets us here for the first time, and occurs again in Isaiah 49:26; Isaiah... read more
Ellicott's Commentary for English Readers - Isaiah 40:4
(4) Every valley shall be exalted.—The figure is drawn from the titanic engineering operations of the kingly road-makers of the East, but the parable is hardly veiled. The meek exalted, the proud brought low, wrong ways set right, rough natures smoothed: that is the true preparation for the coming of the Lord, and therefore the true work of every follower of the Baptist in preparing the way. (Comp. Matthew 3:5-7; Luke 3:3-9.) read more