He said, I am a voice crying in the wilderness, Make straight the way of the Lord, as said Isaiah the prophet. This great utterance had been by the synoptists distinctly applied to the Baptist; here we have the origin of such application.
The Baptist quoted from Isaiah 40:3 two sentences; the synoptists cite the whole passage, as finding abundant realization in the mission of John. The prophet felt that the work he had to perform entirely concealed the importance of his own personality.
He lost himself in his office and in his message. Isaiah, when foreseeing the revival of the nation, then wandering in a spiritual "wilderness," along rugged ridges, savage precipices, stony gorges, of a symbolic desert, anticipated the return of the Jehovah to his own sanctuary, and declared that ample prophetic preparation was needed, so that the people, by repentance and reformation, might understand that Israel had received double for all her sins.
"Hark!" says he, "a crier, or a voice." The herald has gone forth to break the silence that lay between the land of captivity and the land of promise. "In the wilderness prepare ye the way of the Lord."
Israel was to see that there was neither self-righteousness nor moral rebellion to impede the approach of One who was mighty to save. A portion of this very oracle is quoted by Malachi when he exclaims, "Behold, I send my messenger before my face, who shall prepare the way before me."
This "messenger before the face of the Lord" is no other than he who should come in the spirit and power of Elijah. John, therefore, gathered up the significance of both prophecies, when he spoke of himself as "a voice crying in the wilderness [actual and symbolical], Make straight the way of the Lord."
The Hebrew text, as we have translated it above, associates the words, "in the wilderness," with "make straight." rather than with "the voice crying." The quotation by the evangelist from the LXX. will suffer either arrangement of the words.