Musar su I Samuele 25:16

There is another explanation, basically along the same lines. We have already explained that Jacob represented the "beauty of Adam," i.e. a human being at its highest spiritual level. He guarded the flocks of Laban for twenty-two years. All this was in order to extract the two good "drops" (of semen) Laban had ever emitted, i.e the ones from which Leah and Rachel were born. These two drops of semen were the ones that were emitted by Adam and had become mixed with the semen which the serpent had injected into Eve when he had mated with her in גן עדן. [The serpent's part of the semen produced the likes of Laban. Ed.] Similarly, David, who was the re-incarnation of Adam, had to become a shepherd of the flocks belonging to Naval (Abigail's first husband) in order to extract from Naval another drop of semen which had not yet been fertilised, and was latent within Abigail's womb. This is the mystical dimension of Abigail. The original serpent, represented in David's time by Naval, who in turn was the re-incarnation of Laban, possessed the spiritual power to retrieve the spiritual essence Jacob had deposited within Leah. When David appeared on the scene of history, he took Abigail from Naval, [she became David's wife after Naval's death.] David had to guard the sheep of Naval, just as Jacob had to guard the sheep of Laban. This is the hidden meaning of Samuel I 25, 16: חומה היו עלינו גם לילה גם יומם כל ימי היותנו רעים הצאן. "They were a wall about us both by night and by day, all the time we were with them tending the flocks." Thus far the Arizal.