Halakah

Careful observation of what is happening in Matt. 12 shows us that the Jews which were in authority, were questioning Him and His disciples because they were "breaking" the halaka (how to walk in or keep Torah) which the Rabbis had added to the writings of Moses, and they put their halaka (oral law, Talmud, Mishnah, etc.) on the same level of authority and in some cases above what was given by YHWH to Moses. Jump to Matt. 15 to see what Yeshua (Jesus) said to them about their tradition or the tradition of their fathers. The problem has always been man adding to or taking away from what YHWH gave to his chosen, for them to live in Righteousness, not be Righteous. Salvation never has and never will come from walking in Torah, that is only given to those who believe and confess Yeshua as the promised Messiah and ask for forgiveness through His Blood. Legalism is what the Jews then and now, as well as some Christians, think that their "works" of the Law is what saves them. It doesn't. Torah is literally our Father's Instructions and we should want to walk in them (those that apply) out of Love.   These upper level authorities of the Jews were threatened by Yeshua's teaching against their halaka.  This is why they wanted to get rid of Him.  But, this was all known ahead of time and had to happen to fulfill prophecy.