Bs"dAre you unfamiliar with YHWH speaking about the new covenant in the Hebrew Bible?
I know about it.
Even the name "New Testament" is not correct: It points to the new covenant that G.d will make with the Jewish people. Paul claims that this is done through Jesus. Paul says in Hebrews 10:15-17; "Whereof the Holy Ghost is also a witness to us, for after he had said before: This is the covenant that I will make with them, after those days, saith the LORD, I will put My laws in their heart and in their minds will I write them. And their sins and iniquities will I remember no more." This is written in Jeremiah 31:31-34; "Behold, the days come saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah. Not according the old covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt, which my covenant they broke, although I was as a husband to them, saith the LORD. But this shall be the covenant that I make with the house of Israel: After those days, saith the LORD, I will put my law in there inward parts and write it in their hearts, and I will be there G.d, and they shall be my people. And they shall no more each man teach his neighbor, and every man his brother, saying: Know the LORD, for they shall all know me, from the least of them till the greatest, saith the LORD, for I will forgive their iniquity and I will remember their sins no more."
Are we now in the days that everybody knows about the LORD (Y-H-W-H)? That nobody has to teach his neighbor about G.d?
Obviously not!
So even the reference to the new covenant, the "New Testament", is not correct.
See also that the law is very important in the new covenant.