In the context of the letter to the Hebrews, this verse underscores a significant transition from the old covenant, represented by the law, to the new covenant, embodied in Jesus Christ. Under the old covenant, high priests were chosen according to the law, which meant they were human and subject to weaknesses and limitations. These priests had to continually offer sacrifices for their own sins and the sins of the people. However, the new covenant, established by God's oath, appoints Jesus as the high priest. Unlike the human priests, Jesus is perfect, having no sin, and his priesthood is eternal.
This distinction is crucial for understanding the completeness and sufficiency of Jesus' sacrifice. His perfection and eternal nature mean that his intercession for humanity is complete and unending. Believers can have confidence in their relationship with God because it is based on the perfect and eternal priesthood of Jesus. This verse reassures Christians of the superior and lasting nature of Jesus' role as the mediator between God and humanity, offering a foundation of faith that is not dependent on human imperfection but on divine promise.