Is this a textual issue or a translation issue? It’s not just the NAB that has the “priestly” stuff in it, but I’m a little at sea in the KOINE since all by books are currently packed up.
λειτουργὸν leitourgon. Although Strong’s is not infallible it translates this as (3011) “a minister, servant, of an official character; of priests and Levites”. Barnes Notes on the Bible has this to say about it:
“This is not the word which is commonly translated "minister" διάκονος diakonos. This word is properly appropriated to those who minister in public offices or the affairs of the state. In the New Testament it is applied mainly to the Levitical priesthood, who ministered and served at the altar; Hebrews 11:11. It is however applied to the ministers of the New Testament, as discharging "substantially" the same offices toward the church which were discharged by the Levitical priesthood; that is, as engaged in promoting the welfare of the church, occupied in holy things, etc.; Acts 13:2, "as they "ministered" to the Lord and fasted," etc. It is still used in a larger sense in Romans 15:27; 2 Corinthians 9:12.”
Further:
“Ministering - ἱερουργοῦντα hierourgounta. Performing the function of a priest in respect to the gospel of God.” The office of a "priest" was to offer sacrifice. Paul here retains the "language"”.
See post 1199
To my knowledge, the phrase doesn't exist in the manuscripts used for the KJV...Whether it does exist in the Catholic manuscripts I can't recollect at the moment without hunting for it...