If I may use this as an opportunity to either share something (or otherwise be corrected if I am wrong so as an opportunity to learn)...
And please forgive me if I could word this better...
As I understand it - it wasn't found in the law that Moses gave - because Moses gave an incomplete picture of God's law. It was only partly revealed to us at the time.
If we read Matthew 5:17 through to the end of the chapter as though it's all one message I see a different picture...
Mat 5:17-20 Do not think that I have come to destroy the Law or the Prophets. I have not come to destroy but to fulfill. For truly I say to you, Till the heaven and the earth pass away, not one jot or one tittle shall in any way pass from the Law until all is fulfilled. Therefore whoever shall relax one of these commandments, the least, and shall teach men so, he shall be called the least in the kingdom of Heaven. But whoever shall do and teach them, the same shall be called great in the kingdom of Heaven.For I say to you that unless your righteousness shall exceed that of the scribes and Pharisees, you shall in no case enter into the kingdom of Heaven.
I know many take this as Christ abolishing the law. But He specifically states that heaven and earth will pass away - and not one jot or tittle shall pass from the law, and that anyone that teaches otherwise will be called least.
So what does it mean to fulfill the law? I think you've touched on it above because Moses didn't give us the
full law...
Mat 5:21-26 You have heard that it was said to the ancients, "You shall not kill" —and, "Whoever shall kill shall be liable to the judgment." But I say to you that whoever is angry with his brother without a cause shall be liable to the judgment. And whoever shall say to his brother, Raca, shall be liable to the sanhedrin; but whoever shall say, Fool! shall be liable to be thrown into the fire of hell. Therefore if you offer your gift on the altar, and there remember that your brother has anything against you,leave your gift there before the altar and go. First be reconciled to your brother, and then come and offer your gift. Agree with your adversary quickly, while you are in the way with him; that the opponent not deliver you to the judge, and the judge deliver you to the officer, and you be thrown into prison.Truly I say to you, You shall by no means come out from there until you have paid the last kodrantes.
So here, it appears as though Moses only gave us part of the law. Moses dealt with an action (don't Kill) - but Jesus came and said this isn't about your action - to fulfill the law (to complete it) - you need to understand it's about your heart - and simply withholding your hand isn't enough.
Likewise he goes on with numerous examples. Moses talked about Adultery as a physical act only. He only gave us part of a view of the moral law. Jesus came and completed what Moses started - finishing the rest of the law for us showing that Adultery isn't about the physical act - but again, we can break this same law without a physical action by thought alone.
Jesus completed what Moses had started. And this law remains now - and will even when heaven and earth pass away - because outside of Jesus - it is by this law men will be condemned. It's what defines sin.
Thus the rich ruler believed that he had kept the commandments - but when we see Jesus fulfilling the law (by reading this in a single reading) - we see that Jesus raised the bar - and showed us that the law is far tougher than what even Moses gave. It's completely unobtainable for us as people.
Thus the
good news. We can't keep this law, but Christ can for us. This law will condemn us outside of Jesus, so we so desperately need Him.
Of course we also know that Jesus was sinless as well - so He didn't just complete the law for us - He lived it and met all criteria for the law - but when I read those scriptures without stopping - it seems that the whole lot flows together - fulfilling the law along with the bar that Jesus raises.
If this is not the case, can someone please explain what did Jesus mean by saying:
"Therefore whoever shall relax one of these commandments, the least, and shall teach men so, he shall be called the least in the kingdom of Heaven".
When I read this - it seems that before Jesus started - He knew that this was going to be a topic of controversy that many people would misunderstand it's purpose. He did everything possible to warn people of this impending mistake including stating that heaven and earth will pass away first, and warns anyone who teaches otherwise will be called least in the kingdom.
Or was that part only for 3 years between then and Christ's death - and then it's no longer relevant?
Or does what Jesus said here in Matthew 5 still apply now?
Again - I am not advocating that we must keep the law to earn salvation - that's impossible, but to understand that the law is still alive and ready to condemn anyone who would reject Jesus Christ's sacrifice.
I firmly believe scripture does not contradict scripture. This understanding seems to fit in with other verses about the law - both it no longer been relevant to us (for salvation), but that it is also a schoolmaster - and still exists and will condemn the unsaved.
As I also understand - God's moral law has always been. It wasn't established by Moses. Moses simply gave us a glimpse of what has always been. What Cain did in Genesis was sin - even before Moses penned 'Thou shall not kill'. Likewise there were clean and unclean animals prior to Moses - when Noah was told to bring in 7 pairs of clean, and 1 pair of unclean animals.
Moses showed us a lot - but it was never completed until Jesus came and showed us the full meaning.