Chapter XXVII.--Why God taught the same things by the prophets as by Moses.
And Trypho said, "Why do you select and quote whatever you wish from the prophetic writings, but do not refer to those which expressly command the Sabbath to be observed? For Isaiah thus speaks: If thou shalt turn away thy foot from the Sabbaths, so as not to do thy pleasure on the holy day, and shalt call the Sabbaths the holy delights of thy God; if thou shalt not lift thy foot to work, and shalt not speak a word from thine own mouth; then thou shalt trust in the Lord, and He shall cause thee to go up to the good things of the land; and He shall feed thee with the inheritance of Jacob thy father: for the mouth of the Lord hath spoken it.' " 
And I replied, "I have passed them by, my friends, not because such prophecies were contrary to me, but because you have understood, and do understand, that although God commands you by all the prophets to do the same things which He also commanded by Moses, it was on account of the hardness of your hearts, and your ingratitude towards Him, that He continually proclaims them, in order that, even in this way, if you repented, you might please Him, and neither sacrifice your children to demons, nor be partakers with thieves, nor lovers of gifts, nor hunters after revenge, nor fail in doing judgment for orphans, nor be inattentive to the justice due to the widow, nor have your hands full of blood. For the daughters of Zion have walked with a high neck, both sporting by winking with their eyes, and sweeping along their dresses.  For they are all gone aside,' He exclaims, they are all become useless. There is none that understands, there is not so much as one. With their tongues they have practised deceit, their throat is an open sepulchre, the poison of asps is under their lips, destruction and misery are in their paths, and the way of peace they have not known.'  So that, as in the beginning, these things were enjoined you because of your wickedness, in like manner because of your stedfastness in it, or rather your increased proneness to it, by means of the same precepts He calls you to a remembrance or knowledge of it. But you are a people hard-hearted and without understanding, both blind and lame, children in whom is no faith, as He Himself says, honouring Him only with your lips, far from Him in your hearts, teaching doctrines that are your own and not His. For, tell me, did God wish the priests to sin when they offer the sacrifices on the Sabbaths? or those to sin, who are circumcised and do circumcise on the Sabbaths; since He commands that on the eighth day--even though it happen to be a Sabbath-- those who are born shall be always circumcised? or could not the infants be operated upon one day previous or one day subsequent to the Sabbath, if He knew that it is a sinful act upon the Sabbaths? Or why did He not teach those--who are called righteous and pleasing to Him, who lived before Moses and Abraham, who were not circumcised in their foreskin, and observed no Sabbaths--to keep these institutions?"