And so, when the Hebrew infant was circumcised, it signified for him and for his parents these spiritual realities. It was an outward sign and seal of the covenant of God with Abraham and with his seed, to be a God to him and to his seed after him; and it signified further that this covenant of God was to be carried out and made effectual only through the putting away of the flesh, the corrupt nature with which we are born, and of all that belongs to it, in order that, thus circumcised with the circumcision of the heart, every child of Abraham might indeed be an Israelite in whom there should be no guile.
And the law commands, in accord with the original command to Abraham, that the circumcision should take place on the eighth day. This is the more noticeable, that among other nations which practised, or still practise, the rite, the time is different. The Egyptians, for example, circumcised their sons between the sixth and tenth years, and the modern Mohammedans between the twelfth and fourteenth year. What is the significance of this eighth day?
In the first place, it is easy to see that we have in this direction a provision of God's mercy; for if delayed beyond infancy or early childhood, as among many other peoples, the operation is much more serious, and may even involve some danger; while in so early infancy it is comparatively trifling, and attended with no risk.
Further, by the administration of circumcision at the very opening of life, it is suggested that in the Divine ideal the grace which was signified thereby, of the cleansing of nature, was to be bestowed upon the child, not first at a late period of life, but from its very beginning, thus anticipating the earliest awakening of the principle of inborn sin. It was thus signified that before ever the child knew, or could know, the grace that was seeking to save him, he was to be taken into covenant relation with God. So even under the strange form of this ordinance we discover the same mind that was in Him who said concerning infant children (Luke xviii. 16): "Suffer the little children to come unto Me, and forbid them not: for of such is the kingdom of God." Thus we may well recollect, in passing, that, although the law has passed away in the Levitical form, the mind of the Lawgiver concerning the little children of His people, is still the same.
But the question still remains, Why was the eighth day selected, and not rather, for instance, the sixth or the seventh, which would have no less perfectly represented these ideas? The answer is to be found in the symbolic significance of the eighth day. As the old creation was completed in six days, with a following Sabbath of rest, so that six is ever the number of the old creation, as under imperfection and sin; the eighth day, which is the first day of a new week, everywhere in Scripture appears as the number symbolic of the new creation, in which all things shall be restored in the great redemption through the Second Adam. The thought finds its fullest expression in the resurrection of Christ, as the First-born from the dead, the Beginning and the Lord of the new creation, who in His resurrection-body manifested the first-fruits in physical life of the new creation, rising from the dead on the first, or, in other words, the day after the seventh, the eighth day. This gives the key to the use of the number eight in the Mosaic symbolism. Thus in the law of the cleansing of the man or the woman that had an issue, the sacrifices which effectuated their formal deliverance from the curse under which, through the weakness of their old nature, they had suffered, were to be offered on the eighth day (xv. 14, 29); the priestly cleansing of the leper from the taint of his living death was also effected on the eighth day (xiv. 10); so also the cleansing of the Nazarite who had been defiled by the dead (Numb. vi. 10). So also the holy convocation which closed the feast of tabernacles or ingathering--the feast which, as we shall see, typically prefigured the great harvest of which Christ was the First-fruits--was ordained, in like manner, for the eighth day (xxiii. 36). With good reason, then, was circumcision ordered for the eighth day, seeing that what it symbolically signified was precisely this: the putting off of the flesh with which we are born through the circumcision of Christ, and therewith the first beginning of a new and purified nature--a change so profound and radical, and in which the Divine efficiency is so immediately concerned, that Paul said of it that if any man was in Christ, in whose circumcision we are circised (Col. ii. 11), "there is a new creation" (2 Cor. v. 17, margin, R.V.).