The gospels report him engaging in debate especially about Shabbat observance
Regarding the Shabbat observance, I have found this:
“By Jesus’ day, the rabbis and scribes had become so strict that they accused Jesus’ disciples of breaking the Sabbath because they picked some grain and ate it as they walked through a field on the Sabbath (
Luke 6:1 – 2).
The Pharisees said to him, “Look, why are they doing what is unlawful on the Sabbath?” [Jesus] answered, “Have you never read what David did when he and his companions were hungry and in need? In the days of Abiathar the high priest, he entered the house of God and ate the consecrated bread, which is lawful only for priests to eat. And he also gave some to his companions. Then he said to them, “The Sabbath was made for man, not man for the Sabbath. So the Son of Man is Lord even of the Sabbath.”
(Mark 2:24-28)
Jesus’ healings on the Sabbath upset the religious teachers who classified healing as “work” and therefore prohibited it (
Mark 3:1-6)
Jesus said that God had given the Law to encourage the Israelites to love him and to love others. God had never prohibited doing good on the Sabbath ...
Jesus and the Sabbath
ritual handwashing before meals,
Regarding ritual handwashing, Jesus’s attitude is expressed in Mark 7:1-8
(
Please: this is not intended as a criticism of Judaism; it is just what Jesus is supposed to have said about practices in his own time):
“The Pharisees and some of the teachers of the law who had come from Jerusalem gathered around Jesus and saw some of his disciples eating food with hands that were defiled, that is, unwashed.
(The Pharisees and all the Jews do not eat unless they give their hands a ceremonial washing, holding to the tradition of the elders. When they come from the marketplace they do not eat unless they wash. And they observe many other traditions, such as the washing of cups, pitchers and kettles.)
So the Pharisees and teachers of the law asked Jesus, “Why don’t your disciples live according to the tradition of the elders instead of eating their food with defiled hands?”
He replied, “Isaiah was right when he prophesied about you hypocrites; as it is written:
These people honour me with their lips,
but their hearts are far from me.
They worship me in vain;
their teachings are merely human rules.
You have let go of the commands of God and are holding on to human traditions.”
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In Matthew 19:8 Jesus condemns divorce except in case of sexual unfaithfulness:
“I tell you that anyone who divorces his wife, except for sexual immorality, and marries another woman commits adultery”
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In Mark 10:11-12 which is supposed to have been written before Matthew, he condemns it outright:
“Anyone who divorces his wife and marries another woman commits adultery against her. And if she divorces her husband and marries another man, she commits adultery.”
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It appears Jesus said nothing directly, but in Ephesians 6:1 Paul writes:
Children, obey your parents in the Lord, for this is right. "that it may go well with you and that you may enjoy long life on the earth." Fathers, do not exasperate your children; instead, bring them up in the training and instruction of the Lord.
the concept of righteousness in the context of keeping the commandments received by Moses.
Again I can’t find direct comments by Jesus, except as a negative reaction to the observance of the letter as opposed to the spirit of the law. But It is discussed by Paul in
Romans 10
