Origen of Alexandria : The fifth song after these is in the second book of Kingdoms, when David spoke to the Lord the words of this song in the day in which the Lord delivered him from the hand of all his enemies, and from the hand of Saul, and he said: "The Lord is my rock and my fortress, the Lord my deliverer, my God shall be my keeper." If, then, you too can consider who are the enemies of David whom he overcomes and lays low in the first and second book of Kingdoms … then you too will be able to sing that fifth song. — COMMENTARY ON THE SONG OF SONGS, PROLOGUE