John Gill 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, shall be called the Prophet of the Highest ,
&c.] Here Zacharias turns himself to his son John, though an infant, and incapable of knowing what was said to him; and for the sake of those that were present, describes his office and work; and says, that he should be "called", that is, that he should "be", and be accounted a "prophet": for he was not only a preacher of Christ and his Gospel, but he also foretold the coming of the Messiah; and the vengeance that should fall on the Jewish nation, for their unfruitfulness, impenitence, and unbelief: and the Prophet "of the Highest"; that is, of God; as the Persic version renders it, of the most high God;

and by whom is meant, the Lord Jesus Christ, whose prophet, harbinger, and forerunner John was; and so is a proof of Christ being the supreme, or most high God:

for you shall go before the face of the Lord, to prepare his ways;
as the angel had suggested in (Luke 1:17) and as was prophesied of him in (Isaiah 11:3) (Malachi 3:1) . (See Gill on Matthew 3:3).