and he called the name of it Jehovahnissi; “the Lord is my banner”: alluding to the hands of Moses being lifted up with the rod therein, as a banner displayed, under which Joshua and Israel fought, and got the victory. This may fitly be applied to Christ, who is both altar, sacrifice, and priest, and who is the true Jehovah, and after so called; and who is lifted up as a banner, standard, or ensign in the everlasting Gospel, in order to gather souls unto him, and enlist them under him, and to prepare them for war, and encourage them in it against their spiritual enemies; and as a token of their victory over them, and a direction to them where they shall stand, when to march, and whom they shall follow.

(Commentary from John Gill’s Exposition of the Bible)