Psalms 132:17

(17) Horn of David.—The sprouting or growing horn is an image of young, vigorous life. (See Note, Psalms 75:5.) The Messianic application of this prediction comes out in Zechariah’s song (Luke 1:69).

I have ordained a lamp.—Or, I have trimmed a lamp; the word used in connection with the sacred lights, under the express charge of Aaron and his sons (Exodus 27:21; Leviticus 24:2-3). But with this distinctly sacerdotal allusion we must also combine the special allusion to the Davidic dynasty, according to the promise (1 Kings 11:36): “That David my servant may have a light (or, lamp, as here) always before me in Jerusalem.”