I don’t believe the Gospel of Matthew has been quoted on this thread, either by myself, or anyone else.
My bad.

But the account you quoted from St Mark’s gospel also occurs in St Matthew’s gospel, as I’m sure you realise.
where does Jesus refer to the authority of the High Priest, the Pharisees, and the Scribes as “tradition?” Answer: He doesn’t
Am I understanding you correctly? Are you implying that the Pharisees never knew they sit on Moses’ seat? That Jesus was telling his listerners something that they never knew?

The context of the passage indicates very clearly that the Pharisees claimed such authority for themselves, and that Jesus, in this instance, did not disagree. Where would they base such a claim upon?
But I will help you to do your homework: Jesus was clearly relying on a Pharasaic tradition that claims such an authority:
The Jewish rabbis claimed to have received divine revelation and the authority to interpret it in an unbroken line from Moses (cf. Pirke Aboth [The Sayings of the Fathers] 1,1) translated by John Meier, New Testament Message: Matthew
The Pharisees claimed this, this is not written in the OT, but is part of Jewish tradition (written in the Mishnah), Jesus accepts it. Thus Jesus accepts that God’s plan can also be found in unwritten traditions apart from Scripture. How circular a reasoning was this?
And what would that “fatal flaw” be?
St Paul obviously believed that the “rock that followed” the Israelites around the desert was a prefigurement of Christ. But St Paul would make sense
only if the Jews already accepted that there was a physical rock that actually travelled with the people. St Paul then shows that the rock was a symbol for Christ, just as the crossing of the Red Sea (another historical event) was a symbol for baptism. Perhaps I’m misreading you, but clearly, the Jews didn’t share St Paul’s convictions that the rock was Christ. They probably thought it was a marvellous miracle from God that the rock moved with them to provide water, a testament of God’s providence and care.
ISTM, you’re working back to the argument of Bellarmine.
Sorry, what’s “ISTM”? Not very familiar with these short forms.
Paul spoke of “tradition,” singular, not plural as you write above. And, all one need do is read from v1 of chapter 2 to find the “tradition” of which Paul was speaking.
You cannot prove that the “tradition” spoken of in the NT, is anything other than that which was written down.
I’m sorry, but you lost me completely at this point.

In 2 Thessalonians, we read:
So then, brothers, stand firm and hold to the teachings[footnote: traditions] we passed on to you, whether by word of mouth or by letter. niv
So then, brethren, stand firm and hold to the traditions which you were taught, whether by word of mouth or by letter from us. nasb
Therefore, brethren, stand fast and hold the traditions which you were taught, whether by word or our epistle. nkjv
So then, brothers and sisters, stand firm and hold fast to the traditions that you were taught by us, either by word of mouth or by our letter. nrsv
So the English translation clearly speaks of
traditions in the plural. Similarly in St Jerome’s Vulgata translation. Clearly, St Paul was envisioning something more than the one tradition that you seem to harp on. And since St Paul was speaking of traditions whether orally communicated
or written, the content of these traditions must extend beyond what was mentioned and beaten to a dead horse in 2 Thess. To insist that all the traditions that St Paul intends to cover can also be found in 2 Thess is neither proper reasoning, nor circular reasoning, but a failure to use common sense to reason.
You gotta’ love a Catholic who attacks God’s in word in the manner in which you do.
Your apologetic is quite devilish, IMO. Good job!
Oh dear, you didn’t seem to understand gentle irony. If you read carefully, you would realize that I accept fully Scripture as the written Word of God on the authority of the teaching of the Catholic Church.
In any case, it was
you who agreed with Whitaker’s proposition and demanded that Catholics somehow prove that the Tradition we have is what St Paul mentioned. I don’t agree with Whitaker’s proposition and have my preliminary answer to him, but I would like to have that matured before I embarass myself publicly on that. I merely pointed out that anyone who accepts Whitaker’s argument must,
if he is intellectually honest, also grapple with the question of how he can prove that the canonical Scriptures are really true. So either you really don’t agree with Whitaker, thus disproving the validity of his argument, or you really don’t believe in the Scriptures. Of course, it is possible that you have not thought fully about what you support, or you are lying to yourself.