Bible Gateway:
https://www.biblegateway.com/passage/?search=Luke+1%3A67-80&version=AMP
T.H.M.Commentary:- In the Old Testament a HORN is a symbol of strength.
“Jesus IS the Horn of Salvation” from Desiring God by John Piper:
https://www.desiringgod.org/messages/jesus-is-the-horn-of-salvation

Bible Hub Commentary Luke 1:69
https://biblehub.com/commentaries/luke/1-69.htm
Ellicott's Commentary for English Readers
(69) Hath raised up an horn of salvation.—The symbolism of the horn comes from Psalm 132:17, where it is used of the representative of the House of David, and answers to the “Anointed” of the other clause of the verse. It originated obviously in the impression made by the horns of the bull or stag, as the symbols of strength. Here, following in the steps of the Psalmist, Zacharias uses it as a description of the coming Christ, who is to be raised up in the House of David.