Bede : And David said to Achis: Now you will know, etc. It is clear according to the letter, because David, promising aid to the king, also promises to be his guardian, whether in the battle or after the victory. But according to the spiritual sense, the head of the strong brothers and those acting manfully is Christ. To whom, he saying, And behold, I am with you always, even to the end of the age (Matthew XXVIII); they respond: And we have learned that no one should be our guardian of the grace leading us, by which you remain in us, other than yourself, not only on all the days of this age, but also in the future, where one day in your courts is better than thousands (Psalm LXXXIII). — Commentary on Samuel