Correct: Luke 21.30-31. And no, I do not think any manuscripts of Luke have "men". However, codex Bezae has the passive voice, "it is known", rather than "you know". I suppose that could derive either from an original "you know" or from an original "men know".
That shows for me "men" comes from Tertullian and no others. And if Tertullian had "men" in "the picture presented in the parable", he probably also originated "fruit" in it, inadvertently introducing something stupid (all fruit trees produce fruit when summer is approaching).
Of course, I cannot be certain about this, but that seems likely, in view that gospels which are early in my book (1st century) do not have "fruit" in that parable.
Something I just found, thanks to Peter's catena, that Tertulian wrote in 'The Resurrection of the Flesh' Ch. 22:
" For after He had declared that "Jerusalem was to be trodden down of the Gentiles, until the times of the Gentiles should be fulfilled
[only in gLuke
],"--meaning, of course, those which were to be chosen of God, and gathered in with the remnant of Israel--He then goes on to proclaim, against this world and dispensation (even as Joel had done, and Daniel, and all the prophets with one consent), that "there should be signs in the sun, and in the moon, and in the stars, distress of nations with perplexity, the sea and the waves roaring, men's hearts failing them for fear, and for looking after those things which are coming on the earth." "For," says He, "the powers of heaven shall be shaken; and then shall they see the Son of man coming in the clouds, with power and great glory. And when these things begin to come to pass, then look up, and lift up your heads, for your redemption draweth nigh." He spake of its "drawing nigh," not of its being present already; and of "those things beginning to come to pass," not of their having happened: because when they have come to pass, then our redemption shall be at hand, which is said to be approaching up to that time, raising and exciting our minds to what is then the proximate harvest of our hope. He immediately annexes a parable of this in "the trees which are tenderly sprouting into a flower-stalk, and then developing the flower, which is the precursor of the fruit." "So likewise ye," (He adds), "when ye shall see all these things come to pass, know ye that the kingdom of heaven is nigh at hand." ..."
http://www.earlychristianwritings.com/t ... ian16.html
Here, there are no doubts Tertullian "innovated" on Lk 21:30a.
My argument from the phrase so also you is exactly the opposite; there is nothing actually incorrect about it, since "you" can easily both know your fruit trees and know your signs of the oncoming apocalypse. That is not the issue. The issue is that there is something awkward in the way it is worded, something that implies it was originally worded differently (it certainly should have been worded differently), and Marcion happens to have the wording we might expect.
I think there is a problem. Yes ""you" can easily both know your fruit trees and know your signs of the oncoming apocalypse". But could it be the same "you"?
The "you" in 21:29 are the four disciples on the mount of Olives with Jesus (or "men" if you still think Tertullian quoted gMarcion here). Does not matter. Both would easily know about the fructification of fruit trees (of the trees getting new leaves).
But then, the "you" of "so also you" or "so, likewise, you", if it still means the four disciples, then that would imply this foursome would be believed still alive when the gospels were written, which would be quite a stretch for gLuke, gMatthew (written around 85-90, some say later), and even more so for gMarcion. That would mean that Jesus was a false prophet, because he predicted the apocalypse will happen before the disciples died.
How to explain that?
I think "Mark" had Jesus out of character by addressing Christians alive in 70-71 CE with "so also you", as he had Jesus doing the same (twice) earlier in the same mini-apocalypse discourse with "let the reader understand" and "now" instead of "then".
Furthermore the "you" in "so also you" is emphatic, which would not be expected, if the "you" refers to the same four disciples.
What about "Luke" & "Matthew". Either they, and their communities, still wanted to believe the foursome was still alive (as I said, a stretch), or they blindly copied gMark, that is without thinking of the implications.
As for Marcion, the only option I can see is he blindly copied gLuke.
Your argument in the case of Luke 16.17 that "my words" is what we would expect of Marcion, and that therefore he must have made the change instead of Tertullian wording it that way, is perilous. If the question is whether Marcion has basically preserved his text or mutilated it (and that is certainly the question I am asking here), then one cannot, must not, simply assume that Marcion made the change because the wording is congenial to him; to do so is to assume your conclusion.
Do you know of any ancient manuscripts which would have "my words" in Lk 16:17?
I do not think it is wrong to assume Marcion made changes in order to avoid text against his views. BTW, that verse is not only in gLuke but also in gMatthew (5:18), in both cases, with the tittle related to the Law (of Moses).
Tertullian had no reason to make a change here, but Marcion certainly had.
And you did say:
"Marcion apparently has "one tittle of my (Jesus') words", yet a "tittle" (Greek κεραία) is a written mark, a stroke or a serif on certain letters. Such a term makes far more sense when applied to the law, which had been written for centuries, than it does applied to Jesus' own (as yet unwritten) words while he is still speaking them. ..."