Hebrews 7:20-25

This new system was established with a solemn oath. Aaron’s descendants became priests without such an oath, but there was an oath regarding Jesus. For God said to him, “The LORD has taken an oath and will not break his vow: ‘You are a priest forever.’” Because of this oath, Jesus is the one who guarantees this better covenant with God. There were many priests under the old system, for death prevented them from remaining in office. But because Jesus lives forever, his priesthood lasts forever. Therefore he is able, once and forever, to save those who come to God through him. He lives forever to intercede with God on their behalf.