He was covering only the original 10 commandments, you would know that if you were familiar with Jesus at all.
Yeah, that's about the twist I expected you'd put on it, I've seen it before, and I also expected some gratuitous little slap at what you think is my ignorance. You never can resist the ad hominem fallacy.
That's plainly not what the book says. It's in Matthew, (and affirmed in Luke as well) as you know:
5:17 Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.
5:18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.
5:19 Whosoever therefore shall break one of these least commandments...
It's clear that in verses 17 and 18 he's talking about the whole body of the law, but then the use of word "commandments" in verse 19 allows you to exempt everything but the Ten Commandments from what he's saying. If he's not come to destroy the law but to fulfill it, he cannot be talking about only the Big Ten and repealing everything else. Also, if he were talking only about the Big Ten, the modifying phrase "one of these least" would not be there. He means all of it. There are other claims, in both the Old and New Testaments, that both support and deny the argument that the OT laws apply forever. The book's not consistent, as you'd expect if it were a work of men. And it is.