Charles Ellicott Commentary Luke 1:67

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

Was filled with the Holy Ghost, and prophesied.—The latter word appears to be used in its wider sense of an inspired utterance of praise (as, e.g., in 1 Samuel 19:20; 1 Corinthians 14:24–25). The hymn that follows appears as the report, written, probably, by Zachariah himself, of the praises that had been uttered in the first moments of his recovered gift of speech. As such, we may think of it as expressing the pent-up thoughts of the months of silence. The fire had long been kindling, and at last he spoke with his tongue.