LIX. In order that the idea of the contracted covenant might remain firmly impressed on all Abraham's progeny, it was necessary to institute some external mark, which should continually recall it to the mind; for an idea being but an abstraction, it could not be very long retained in men's minds, without some symbol or visible sign capable of keeping its remembrance alive. It was also necessary that the adhesion of that progeny to the covenant should not begin to take effect in individuals in the adult age only, and as a result of one's own spontaneous reflexions, as had been the case with the first stock of that family, but that it should present itself as an accomplished fact, and, therefore, irrevocable and obligatory; so that every future offspring should bear from his birth an external indelible mark, characterising him as a follower of that principle, and qualifying him to enter into the pale of that association. By such means the preservation of the covenant was insured, and a beginning was made in the system of those external, symbolical, and commemorative acts, which were to be thereafter prescribed to all that race, when sufficiently increased to form an entire people distinct from others. This external mark, instituted before the birth of the elect progeny of the patriarch, is the _circumcision_. LX. Before Abraham's descendants attained that degree of maturity which would fit them to receive a revealed legislation, they had to pass through various stages of progressive material increment and intellectual development, and also to undergo several sad vicissitudes produced by the inevitable relations of contact with other nations. Throughout all this period, which we may call preparatory, the Divine Wisdom was pleased to take that race by the hand, guiding its first steps, and watching in an extraordinary manner over its destinies, so as gradually to prepare it for the high mission for which it was designed. We, therefore, perceive, during that epoch, a continual intervention of the Divinity in regulating the particular concerns of the patriarchs and their successors, and an incessant care to draw their attention to the future destiny of their grandchildren, and to their duty of preparing worthily for it. Such a care manifested itself, particularly, in various providential measures, the objects of which evidently were to remove from them everything that might exercise over them a sinister influence; to enlighten them on the importance of their election, and to make them acquainted beforehand with the severe trials in store for them for several centuries, before they could deservedly reap the intended benefits.