A prooftext for sola scriptura it is not, -- it has nothing to do with it, other than to mantion the fact that this particular piece of instruction Paul is delivering in writing. You are familiar with the passage where he states that he is writing because he is delayed in coming, the implication being that he'd rather be present in person?
Yet Paul is clearly talking about what he is WRITING being the instructions on how to behave in the Church - correct?
IN other words, this is a section of the canon of the New Testament which endorses the use of this WRITTEN letter we are reading - inspired by the Holy Spirit - written down by Paul == to instruct the CHURCH on how it is to conduct itself.
Correct?