John 1:29
What is strange is that the probably interpolated incipit of Revelation puts the visions & revelations about the Lamb on the mouth of the disciple John.
While according to John 1:29, it's John the Baptist who sees the mystical Lamb of Revelation.
In whiletime, the pauline "Mark" despises the Pillars by calling them "the sons of thunder", caustic reference to Revelation. Hence I think, with Couchoud, that the Mark/Mcn line of tradition connected firstly the Book of Revelation with a precise figure named John, one of the Pillars.
This connection (even if clearly sarcastic in the mind of "Mark") reflects the historical reality about the followers of the Pillars, who combated the paulines (both the pauline adorers of YHWH and the pauline haters of YHWH) by using the Book of Revelation et similia as propaganda.
Hence the question: why does the Fourth Gospel place the basic item of Revelation (=the vision of the mystical Lamb) on the mouth of John the Baptist, and not of John son of Zebedee?
I think that the author of the Fourth Gospel was reacting against the proto-catholic interpolation of the incipit of the Book of Revelation, an incipit that connected - but in a positive sense (as opposed to the negative sense meant by Mark and Marcion) - the Pillar John with the Book of Revelation. The proto-catholics, by connecting that book with the Pillar John, were co-opting the Jewish-Christian tradition of the Pillars (as reflected in Revelation) even if they, adopting Mark and Matthew, were co-opting also a Pauline tradition basically hostile to the Book of Revelation.
So what the Fourth Gospel does basically, by John 1:29?
The message is strongly anti-catholic: the vision of the mystical Lamb was not the property of the Gospel Pillars, especially when these Gospel figures are became catholicized by proto-catholics.
The fact that John the Baptist saw the mystical Lamb means simply that the vision of the mystical Lamb preceded the birth of Christianity (being John the Baptist the precursor par excellence).