Every valley shall be filled, and every mountain and hill shall be brought low; and the crooked shall be made straight, and the rough ways shall be made smooth; Every they shall be filled - All hinderances shall be taken out of the way: a quotation from the Greek version of Isaiah 40:4, containing an allusion to the preparations made in rough countries to facilitate the march of mighty kings and conquerors. See the instance produced on Matthew 3:3 (note).
Related Commentaries of Luke 3:5
Luke 3:5
5 Every valley shall be filled, and every mountain and hill shall be brought low; and the crooked shall be made straight, and the rough ways shall be made smooth;