Ye shall not add unto the word which I command you. Deuteronomy 4:2
Don't be angry with your brother or call him a fool.
Ye have heard that it was said of them of old time, Thou shalt not kill. ...
But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and ... whosoever shall say, Thou fool, shall be in danger of hell fire. Matthew 5:21-22
Don't look at a woman with lust.
Ye have heard that it was said by them of old time, Thou shalt not commit adultery:
But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart. Matthew 5:27-28
Don't divorce your wife (unless she has committed fornication, according to Matthew; for any reason, according to Luke and Paul). And don't marry a divorced woman.
It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement: But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery: and whosoever shall marry her that is divorced committeth adultery. Matthew 5:31-32
Whosoever putteth away his wife, and marrieth another, committeth adultery: and whosoever marrieth her that is put away from her husband committeth adultery. Luke 16:18
And unto the married I command, yet not I, but the Lord, Let not the wife depart from her husband: But and if she depart, let her remain unmarried or be reconciled to her husband: and let not the husband put away his wife. 1 Corinthians 7:10-11
Don't swear at all.
Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths:
But I say unto you, Swear not at all; neither by heaven; for it is God's throne:
Nor by the earth; for it is his footstool: neither by Jerusalem; for it is the city of the great King.
Neither shalt thou swear by thy head, because thou canst not make one hair white or black. Matthew 5:33-36
Turn the other cheek.
Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth:
But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also. Matthew 5:38-39
Love your enemies.
Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy.
But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you. Matthew 5:43-44