No one is talking about extra scriptural writings, I'm saying along with St. Paul there are other teachings outside of the Bible that must be kept, and this being so means Sola Scriptura is false:
2Thes:2:15: Therefore, brethren, stand fast: and hold the traditions, which you have learned, whether by word or by our epistle.
Paul also mentions the church as being the pillar and ground of truth not scripture alone:
1Tm:3:15: But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth.
This pillar and ground of truth is what tells me the Scriptures are the Word of God.
The word tradition in the Greek means literally things handed down. That’s all it means. Things handed down. And what he is saying then in that sense is this, stand firm and hold on to the things handed down, the things handed down through teaching by word and letter from us.
That’s divine revelation. In the Pauline letters and the revelation God gave him which he preached to them...the oral things and the written things.