Albert Barnes Commentary Luke 1:76

"Yea and thou, child, shalt be called the prophet of the Most High: For thou shalt go before the face of the Lord to make ready his ways;" — Luke 1:76 (ASV)

And you, child, ... Zacharias predicts in this and the following verses the dignity, the employment, and the success of John. He declares what would be the subject of his preaching, and what his success.

Prophet of the Highest. Prophet of God; a prophet appointed by God to declare his will, and to prepare the way for the coming of the Messiah.

The face of the Lord. This refers to the Lord Jesus, the Messiah, who was about to appear. To go before the face of someone is the same as to go immediately before that person, or to be immediately followed by another.

To prepare his ways. This is taken from Isaiah 40:3; see Barnes on Matthew 3:3.

See Barnes on Isaiah 40:3.