This is He who was spoken of through the prophet Isaiah, A voice of one calling in the wilderness, ‘Prepare the way for the Lord, make straight paths for Him.’ Matthew 3:3

Every valley shall be lifted up, and every mountain and hill made low; the uneven ground will become smooth, and the rugged land a plain. And the glory of the Lord will be revealed, and all people will see it together. For the mouth of the Lord has spoken. Isaiah 40:4-5