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He specifically said he didn't come to abolish the Law. Does that mean you can now commit adultery and covet? Obviously not. Likewise, if Jesus commanded to not defraud, then he's referring to the rest of the Mosaic Law as well.
Also, the mere fact that Jesus mentioned "Do not defraud" implies that more than the 10 commandments were being mentioned as binding commandments. Additionally, Jesus tells the healed Leper to make a sacrifice "As Moses" commanded.
But he said "Do not defraud" In the same sentence as "do not bear false witness". Do not defraud is not in the original 10. Also, the first commandment is different than the second. He also never mentions coveting. So does that mean you can now covet?
Matthew 7:22-23, the "lawless' will be rejected, and he means "those against Mosaic Law", Matthew 5:17-20 means the Law will be forever in effect, same with Luke 16:17. Christianity was completely Jewish until much after Christ dead.
you are welcome. I would encourage you to examine the bibles teachings... people do twist the scriptures and misapply them, so that is why you must check the scriptures yourself. If you have any questions, feel free to ask me and i will do my best to direct you to the scriptures for answers.