Doctrine and Covenants 13

 
1 UPON you my fellow servants, in the name of Messiah I confer the Priesthood of Aaron, which holds the keys of the ministering of angels, and of the gospel of repentance, and of baptism by immersion for the remission of sins; and this shall never be taken again from the earth, until the sons of Levi do offer again an offering unto the Lord in righteousness.
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The Pearl of Great Price, JS-H 1:71 says Joseph and Oliver ordained each other to the Aaronic Priesthood, but it never mentions an ordination to any office in that priesthood.

Also note that it isn't until Joseph receives revelation in 1843 that they learn how to distinguish between angels of God and the devil himself (D&C 129:1-9). How would they know if an angel as mentioned in section 13 was from God or not?

-a-bom