Are you suggesting that matthew is not written to or for us? Just wonderin'.
Actually, I believe he said something to the effect that one jot or one tittle should in no wise pass from the law till all be fulfilled. And in the next verse spoke of someone breaking one of these least commandments, as well.
Since "the law" by definition means one law, or the whole codex, which one was he talking about, since you apparently do not believe he was speaking of the whole ball of wax? Adultery, maybe? Lying? Keeping the Sabbath? Coveting? Dishonor of father and mother? Or one of the other five? Which one is it?
James says something to the same effect, and in fact cites one law that is not a part of the Ten commandments as the example, and in fact speaks of the whole law. My problem is those who prefer to "pick and choose" which ones apply, rather than see that the entire codex was done away in Christ, who personally kept it all perfectly and nailed it to the cross, thereby "taking it out of the way", and the relevant parts - i.e. the necessary principles (as opposed to the Mosaic precepts), are restated for us in the language of grace, or as the NT puts it, "My commandments", "the perfect law of Liberty", or "the law of the spirit of life in Christ Jesus", and is contrasted with the Mosaic law, here spoken of as "the law of sin and death". We do not "keep the law"; rather we are to "fulfill the law", as both Paul and James state. All the above are in the language of 'pure grace'. I have never in any way suggested that we are not to be led by the Spirit via the law of Liberty. I only am not willing to put myself under the curse of the 600 odd precepts of the Mosaic law- "the law of commandments contained in ordinances" and live with Hagar and Ishmael in the wilderness and starve with hunger, when I can be under the "perfect law of liberty" and live in the tents with Sarah and Isaac, and "pig out" and have all the blessings. Why do so many prefer the former? I know "Ah 'on't get it!"
Ed