How does Jesus' role as a High Priest fulfill the Old Testament law?

In the Old Testament, the priesthood served as a mediator between God and Israel, offering sacrifices for sin. Jesus, as our High Priest, embodies and exceeds this role by being both the mediator and the ultimate sacrifice for sin. Hebrews 9 links Jesus’ priestly work to the mercy seat in the tabernacle, highlighting that He reconciles us through His sacrificial death. He fulfills the entire sacrificial system, rendering it obsolete by providing a single, perfect sacrifice for all time, thus establishing a new covenant in His blood.