Dialogue with Trypho
Chapter 27: Why God Taught the Same Things Through the Prophets as Through Moses
And Trypho said, “Why do you choose and quote whatever you wish from the prophetic writings, but do not mention those that explicitly command the Sabbath to be observed? For Isaiah speaks like this: ‘If you turn your foot away from the Sabbaths, so as not to do your pleasure on the holy day, and call the Sabbaths the holy delights of your God; if you do not lift your foot to work, and do not speak a word from your own mouth; then you shall trust in the Lord, and He shall cause you to ascend to the good things of the land; and He shall feed you with the inheritance of Jacob your father: for the mouth of the Lord has spoken it.’ ”
And I replied, "I have overlooked them, my friends, not because these prophecies are against me, but because you have understood, and still understand, that although God commands you through all the prophets to do the same things He also commanded through Moses, it was because of the hardness of your hearts and your ingratitude towards Him that He repeatedly declares them. This was so that, even then, if you repented, you might please Him and neither sacrifice your children to demons, nor be involved with thieves, nor love bribes, nor seek revenge, nor neglect justice for orphans, nor ignore the rights of widows, nor have your hands full of blood. 'For the daughters of Zion have walked with arrogance, making gestures with their eyes and flaunting their attire.
They have all turned aside,' He exclaims, 'they have all become useless. There is none who understands, not even one. They have practiced deceit with their tongues, their throat is an open grave, the poison of snakes is under their lips, destruction and misery are in their paths, and the way of peace they have not known.' So, just as these things were commanded to you at the beginning because of your wickedness, similarly now, due to your constant wickedness or even your increased inclination towards it, He uses the same commands to remind or inform you of it.
But you are a people stubborn and without understanding, both blind and lame, children in whom there is no faith, as He Himself says, honoring 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 sacrifices on the Sabbaths? Or those to sin, who are circumcised and perform circumcision on the Sabbaths; since He commands that on the eighth day—even if it falls on a Sabbath—those who are born shall always be circumcised? Or couldn’t the infants be circumcised one day before or one day after the Sabbath, if He knew it is a sinful act on the Sabbaths? Or why did He not instruct those—who are called righteous and pleasing to Him, who lived before Moses and Abraham, who were not circumcised in their flesh and observed no Sabbaths—to keep these laws?"