XXXVIII. (130) And of what kind they are, he proceeds to show in a few words, deriving his explanation from the natural things of art; for he introduces Agar as filling a leathern bag with water, and giving her child Drink.[Ge 21:19.] Now Agar is the handmaid of Sarah, the new dispensation of perfect virtue; and she is correctly represented so. Since, therefore, having come to the depth of knowledge, which Moses here calls a well, she draws up (filling the soul as if it were a vessel) the doctrines and speculations which she is in pursuit of, wishing to feed her child on the things on which she herself is fed. (131) And Moses, by her child, means, a soul which has lately learnt to desire instruction, and which has, in a manner, just been born to learn. In reference to which, the boy, when he has grown up to man's estate, becomes a sophist, whom Moses calls an archer; [Ge 21:20.] for whatever argument he applies his mind to, at that, as at a target, he shoots all his reasons, as an archer shoots his arrows.