Bede

But David, taking the head of the Philistine, etc. I think it should be understood, according to the letter, that David took care to bring the head of such a strong adversary, which had been cut off, to the rebellious city of Jerusalem, still inhabited by the Jebusites, for no other reason than to terrify those who, trusting in the impregnable firmness or height of the walls, presumed that they could not be overcome by anyone. …

Commentary on Samuel ↗