“And it was not without an oath. For those who formerly became priests were made such without an oath,”
The appointment of Jesus as an eternal priest and thus His priesthood as a never-ending one was significant. It was more significant because it was done with an oath. The oath was necessary as God’s word is always sufficient, but God gave an oath to mark how important this appointment was.
The Aaronic priesthood was not made with an oath, but the priesthood of a new Melchizedek was. This point emphasizes the “better” quality of the new priesthood. It narrows the choice that the Hebrews have in regards to which priesthood to trust with their salvation.
Task for Today: Trust God, even if there was no oath. But, since there is, understand that you have no choice as to which priest to follow with your own sacrifice. Jesus is before God now offering His blood for you. His is the “by far better” priesthood.