I have no idea what the ECFs wanted me to believe or what they said about it. That is not the source of my information on the subject. I have various sources, most of them internal to the Bible.
And no proof that they aren't. It is not a big issue. It changes no truth. It does not change the inerrancy of the Bible.
What does that even mean? "The eyewitness who documented Matthew"?
Is this something the Holy Spirit showed you or a vision. Since I can find no scriptural reference to someone documenting Matthew I have no place to even start tracing back to this religious leader etc. So it is on you to do that so we can all know after all the study done on it since the first century, and the author of Matthew still not definitively known, that only you have found. I'm serious. Let me hear it. Then maybe I will be able to take your investigations seriously.
Is this in the Bible somewhere?
The reason I can quote Paul as validating himself as speaking for God is because Jesus appointed him for that purpose. It was not Paul who gives the first accounting of the Damascus Rd. It was Luke. And there were witnesses when Paul had that experience. "The men who were traveling with him stood speechless, hearing the voice but seeing no one." They led him to Damascus. In Acts 9: 10-15 we have the account of Ananias being sent to Paul to open his eyes and verse 16 the angel saying to Ananias who was afraid to go anywhere near Paul (Saul) "But the Lord said to him, 'Go, for he is a chosen instrument of mine to carry my name to the Gentiles, and kings, and the children of Israel." It is likely Luke was one of the eyewitnesses traveling with Paul as he traveled with him a lot.
Deut 18:20-22 But the prophet who presumes to speak a word in my name that I have not commanded hi to speak, or who speaks in the name of other gods, that same prophet shall die. ANd if you say in your heart, "How may we know the word that the Lord has not spoken?----what a prophet speaks in the name of the Lord, if the word does not come to pass or come true, that is a word that the Lord has not spoken; the prophet has spoken it presumptuously.
Good news. You don't have to reject those verses to believe that the writers of the NT are speaking for God-----which is the same thing as God speaking through them, both OT and NT. The scripture I gave above from Acts, the other scriptures I have been giving you to validate the apostles since first I posted in this thread, show clearly that they are speaking for God. Jesus (God) appointed them and equipped them to do that. What have they spoken that has not come to pass other than the promised consummation which awaits Christ's return? Unless you don't trust God to oversee what his word says and to oversee what goes into it as canon, there is no need to ever question the validity of them speaking for God. They were given the very same proofs of the authority of what they spoke as Jesus was.
2 Cor 12:12 The signs of a true apostle were performed among you with utmost patience, with signs and wonders and mighty works.