91 Of the prophetic significance of the spoiling of the Egyptians, which was done by Moses at the command of the Lord his God, who commands nothing but what is most just, I remember to have set down what occurred to me at the time in my book entitled On Christian Doctrine; to the effect that the gold and silver and garments of the Egyptians typified certain branches of learning which may be profitably learned or taught among the Gentiles. This may be the true explanation; or we may suppose that the vessels of gold and silver represent the precious souls, and the garments the bodies, of those from among the Gentiles who join themselves to the people of God, that along with them they may be freed from the Egypt of this world. Whatever the true interpretation may be, the pious student of the Scriptures will feel certain that in the command, in the action, and in the narrative there is a purpose and a symbolic meaning.
Source: Reply to Faustus the Manichaean (New Advent)