Doesn’t Hebrews 7:12 tell us that the old Law of Moses has been abolished and replaced with a new law?

Hebrews 7:12 states: “For the priesthood being changed, of necessity there is also a change of the law.” The change of the law was not the abolition of the Law of Moses. Rather, it was a change in the law concerning the priesthood. This is made clear in verses 13 through 19.

In the Levitical priesthood, all priests were to be descendants of Aaron, of the tribe of Levi. However, since Jesus Christ “arose from [the tribe of] Judah” (Hebrews 7:14), He could be a priest only if the law restricting priesthood to the family of Aaron (of the tribe of Levi) were changed. Had the law in its entirety been abolished, it is unlikely that the writer of Hebrews would have bothered explaining that a change had occurred in one of the law’s commandments.