A.T. Robertson Commentary John 12:50

"And I know that his commandment is life eternal: the things therefore which I speak, even as the Father hath said unto me, so I speak." — John 12:50 (ASV)

Life eternal (ζωη αιωνιος). See 3:15; Matthew 25:46 for this great phrase. In 6:68 Peter says to Jesus, "Thou hast the words of eternal life." Jesus had just said (6:63) that his words were spirit and life. The secret lies in the source, "as the Father hath said to me" (ειρηκεν).