David is the creative power planted in every person, the Anointed sent out to conquer what looms over a life. He goes forth against the giant, the enemy that seems too large to face, which is any obstacle held as fixed and unbeatable. Saul is the unawakened mind, the sleeping self that watches its own power in action and cannot say where it came from. He asks whose son this youth is because he does not yet know that David is his own.
Abner cannot tell. Neither can a person while he sleeps. The awareness of being fathers this creative power and forgets it did so. To recognize David as one's own son is to know oneself as the father, the I AM, the single source of everything in one's life.