Translated from the Greek
17 And if we come to the legislation of Moses, many of the laws manifest the irrationality, and others the impossibility, of their literal observance. The irrationality (in this), that the people are forbidden to eat vultures, although no one even in the direst famines was (ever) driven by want to have recourse to this bird; and that children eight days old, which are uncircumcised, are ordered to be exterminated from among their people, it being necessary, if the law were to be carried out at all literally with regard to these, that their fathers, or those with whom they are brought up, should be commanded to be put to death. Now the Scripture says: “Every male that is uncircumcised, who shall not be circumcised on the eighth day, shall be cut off from among his people.” And if you wish to see impossibilities contained in the legislation, let us observe that the goat-stag is one of those animals that cannot exist, and yet Moses commands us to offer it as being a clean beast; whereas a griffin, which is not recorded ever to have been subdued by man, the lawgiver forbids to be eaten. Nay, he who carefully considers (the famous injunction relating to) the Sabbath, “You shall sit each one in your dwellings: let no one go out from his place on the seventh day,” will deem it impossible to be literally observed: for no living being is able to sit throughout a whole day, and remain without moving from a sitting position. And therefore those who belong to the circumcision, and all who desire that no meaning should be exhibited, save the literal one, do not investigate at all such subjects as those of the goat-stag and griffin and vulture, but indulge in foolish talk on certain points, multiplying words and adducing tasteless traditions; as, for example, with regard to the Sabbath, saying that two thousand cubits is each one's limit. Others, again, among whom is Dositheus the Samaritan, condemning such an interpretation, think that in the position in which a man is found on the Sabbath day, he is to remain until evening. Moreover, the not carrying of a burden on the Sabbath day is an impossibility; and therefore the Jewish teachers have fallen into countless absurdities, saying that a shoe of such a kind was a burden, but not one of another kind; and that a sandal which had nails was a burden, but not one that was without them; and in like manner what was borne on one shoulder (was a load), but not that which was carried on both.
18. And if we go to the Gospel and institute a similar examination, what would be more irrational than (to take literally the injunction), “Salute no man by the way,” which simple persons think the Saviour enjoined on the apostles? The command, moreover, that the right cheek should be smitten, is most incredible, since everyone who strikes, unless he happen to have some bodily defect, smites the left cheek with his right hand. And it is impossible to take (literally, the statement) in the Gospel about the “offending” of the right eye. For, to grant the possibility of one being “offended” by the sense of sight, how, when there are two eyes that see, should the blame be laid upon the right eye? And who is there that, condemning himself for having looked upon a woman to lust after her, would rationally transfer the blame to the right eye alone, and throw it away? The apostle, moreover, lays down the law, saying, “Is any man called, being circumcised? Let him not become uncircumcised.” In the first place, anyone will see that he does not utter these words in connection with the subject before him. For, when laying down precepts on marriage and purity, how will it not appear that he has introduced these words at random? But, in the second place, who will say that a man does wrong who endeavours to become uncircumcised, if that be possible, on account of the disgrace that is considered by the multitude to attach to circumcision.
All these statements have been made by us, in order to show that the design of that divine power which gave us the sacred Scriptures is, that we should not receive what is presented by the letter alone (such things being sometimes not true in their literal acceptation, but absurd and impossible), but that certain things have been introduced into the actual history and into the legislation that are useful in their literal sense.
19. But that no one may suppose that we assert respecting the whole that no history is real because a certain one is not; and that no law is to be literally observed, because a certain one, (understood) according to the letter, is absurd or impossible; or that the statements regarding the Saviour are not true in a manner perceptible to the senses; or that no commandment and precept of His ought to be obeyed—we have to answer that, with regard to certain things, it is perfectly clear to us that the historical account is true; as that Abraham was buried in the double cave at Hebron, as also Isaac and Jacob, and the wives of each of them; and that Shechem was given as a portion to Joseph; and that Jerusalem is the metropolis of Judea, in which the temple of God was built by Solomon; and innumerable other statements. For the passages that are true in their historical meaning are much more numerous than those which are interspersed with a purely spiritual signification. And again, who would not say that the command which enjoins to “honour your father and your mother, that it may be well with you,” is useful, apart from all allegorical meaning, and ought to be observed, the Apostle Paul also having employed these very same words? And what need is there to speak of the (prohibitions), “You shall not commit adultery,” “You shall not kill,” “You shall not steal,” “You shall not bear false witness?” And again, there are commandments contained in the Gospel which admit of no doubt whether they are to be observed according to the letter or not; e.g., that which says, “But I say unto you, Whoever is angry with his brother,” and so on. And again, “But I say unto you, Swear not at all.” And in the writings of the apostle the literal sense is to be retained: “Warn them that are unruly, comfort the feeble-minded, support the weak, be patient towards all men;” although it is possible for those ambitious of a deeper meaning to retain the profundities of the wisdom of God, without setting aside the commandment in its literal meaning. The careful (reader), however, will be in doubt as to certain points, being unable to show without long investigation whether this history so deemed literally occurred or not, and whether the literal meaning of this law is to be observed or not. And therefore the exact reader must, in obedience to the Saviour's injunction to “search the Scriptures,” carefully ascertain in how far the literal meaning is true, and in how far impossible; and so far as he can, trace out, by means of similar statements, the meaning everywhere scattered through Scripture of that which cannot be understood in a literal signification.
Source: De Principiis (New Advent)