1 Chronicles 15:23 - Joseph Benson’s Commentary on the Old and New Testaments

Berechiah and Elkanah were doorkeepers Were appointed to keep the door of the tent in which the ark was to be put and kept, that no unhallowed person might press in and touch it. And in like manner they were to attend upon the ark in the way, and to guard it from the press and touch of profane hands: for which end these two went before the ark, as their other two brethren, mentioned in the close of 1 Chronicles 15:24, came after it that it might be guarded on all sides.