John Gill Commentary Luke 1:67

"And his father Zacharias was filled with the Holy Spirit, and prophesied, saying," — Luke 1:67 (ASV)

And his father Zacharias was filled with the Holy Ghost ,
etc.] With a spirit of prophecy, as his wife Elisabeth had been before, (Luke 1:41)

and prophesied
saying; the following things, relating to the Messiah, his incarnation and redemption by him; to the accomplishing of the covenant, oath, promise and mercy of God to his people; and to his son, the forerunner of Christ; and to his work and office, in the various parts and branches of it, which he should perform. From which it appears, that the following song is of divine inspiration; and that Zacharias spoke it as he was moved by the Holy Ghost, as the prophets of old did.