Shall be circumcised. — It is stated by Herodotus (Book ii. 104) that the Egyptians were circumcised, and that the Syrians in Palestine confessed that they learned this practice from the Egyptians. Origen, however, seems to limit circumcision to the priesthood (Epist. ad Rom., § ii. 13); and the statement of Herodotus is not only very loose, but his date is too far posterior to the time of Abram for us to be able to place implicit confidence in it. If we turn to the evidence of Egyptian monuments and of the mummies, we find proof of the rite having become general in Egypt only in quite recent times. The discussion is, however, merely of archaeological importance; for circumcision was just as appropriate a sign of the covenant if borrowed from institutions already existing as if then used for the first time. It is, moreover, an acknowledged fact that the Bible is always true to the local colouring. Chaldæan influence is predominant in those early portions of Genesis which we owe to Abram, a citizen of Ur of the Chaldees; his life and surroundings subsequently are those of an Arab sheik; while Egyptian influence is strongly marked in the latter part of Genesis, and in the history of the Exodus from that country. In this fact we have a sufficient answer to the theories which would bring down the composition of the Pentateuch to a late period: for the author would certainly have written in accordance with the facts and ideas of his own times. If, however, Abram had seen circumcision in Egypt, when the famine drove him thither, and had learned the significance of the rite, and that the idea of it was connected with moral purity, there was in this even a reason why God should choose it as the outward sign of the sacrament which He was now bestowing upon the patriarch.
The fitness of circumcision to be a sign of entering into a covenant, and especially into one to which children were to be admitted, consisted in its being a representation of a new birth by the putting off of the old man, and the dedication of the new man unto holiness. The flesh was cast away that the spirit might grow strong; and the change of name in Abram and Sarai was typical of this change of condition. They had been born again, and so must again be named. And though women could not indeed be admitted directly into the covenant, yet they shared in its privileges by virtue of their consanguinity to the men, who were as sponsors for them; and thus Sarai changes her name equally with her husband.