Who did Moses receive the laws, doctrines and ordinances from? He received them from Jesus Christ who was formerly known as Jehovah, the spiritual son of the Father. It's the law Jesus gave Moses and therefore has the right to fulfill the laws making many of them obsolete going forward. He gave Israel (there are 12 tribes, not just Judah) a higher law with the higher priesthood (power of God to administer God's works and ordinances on the earth). Baptism by water and the spirit (holy ghost) replaced circumcision. The other busy body 600 laws were no longer necessary either.
Some clarity is needed as well. Jews are those members of Israel in the Tribe of Judah. JU-dah, JEW-dah. There are 11 other Tribes of Israel. Jesus Christ is part of Judah (Mary) and part (The Father). He has the authority to continue the law of tithing and fast offerings for the poor, the hungry and the needy.