In the 21st part of Justin's dialogue with Trypho, he ends his discourse on circumcision and Jewish rituals by saying that Sabbaths were instituted on account of people's sins and not for a work of righteousness. Sacrifices and oblations were for the same purpose. This is one I have to ponder some because God did institute Sabbath regulations and sacrifices with very specific instructions. The Jewish Sanhedrin in Jesus's day made them more impossible to follow without a sore conscience. But it's the same reason that God rescued Israel from Egypt and made them a nation. Not because they were righteous, but because of his favor. He gave them the rituals because of their hardness of hearts. Actually, in their zeal to keep every rule for the Sabbath, they polluted it by not believing in Jesus and even killing him.
Now that Jesus has come and gone, he has fulfilled the OT law and erased the need to present sacrifices to a priest. Jesus is both the sacrifice and the priest. The insistence of people to follow old Jewish regulations or even today in trying to atone oneself through acts of penance is an insult to God and what he has done with us through Christ. "He has commanded these and such like institutions on account of sinful men, and we must declare Him to be benevolent, foreknowing, needing nothing, righteous and good." God is the source of all things. He does not need our appeasement, especially since most of the Jews brought sacrifices out of habit and not from a heart that truly wanted to serve the Lord.
All these laws and the rite of circumcision were given as a sign. They did not make the people righteous. Abraham and his descendants had to cut off their foreskins as a sign that they belonged to God. Women could not do this. Now that Christ has come, the Holy Spirit's baptism circumcises people spiritually. It is that baptism that makes clean. Christ's blood put an end to the need for our blood. Also, all people can participate. All a person's righteousness is as used menstrual rags. They are gross and unacceptable. No one can come to God offering just that.
Trypho then starts asking questions. Does Justin mean that none of us Jews shall inherit anything on the holy mountain of God?
Justin replies that those who have persecuted and do persecute Christ, if they do not repent, shall not inherit anything on the holy mountain. However, since the Gentiles have believed Jesus, so they will receive the inheritance with the patriarchs and prophets.
Trypho: 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?
Justin: God commands the same thing in both Moses and in the prophets. They both command the same thing. Justin accepts all Scripture.
Trypho complains that he's not answering the question.
Justin: Circumcise yourselves to the Lord and circumcise the foreskin of your heart. Jeremiah 4:3. Only Christ can give your soul the correct circumcision to make you right before God. He is useless to people who insist on observing the law on their own merit. "What need have I of that other baptism, who have been baptized with the Holy Ghost?" Only Christians possess true righteousness because they trust Christ of their sanctification.