Luke 3:4
As it is written in the book of the words of Isaiah the prophet: a voice of one calling in the wilderness, prepare the way for the Lord, make straight paths for him — Isaiah 40:3 is the prophetic anticipation of John's ministry. The quotation in Luke extends further than in Mark to include the universal scope of the salvation announcement. A voice calling: John is defined by his message rather than his identity — the voice whose content is the preparation for the Lord's arrival.