As I understand it?
That scripture (according to Luther) is divinely inspired and that we should use scripture alone to understand Christ’s teachings and ministry.
That’s Solo Scriptura and it’s not what the reformers believed. This nonsense that Sola Scriptura is using the Bible alone needs to stop. Luther said "unless I am convinced by Scripture...". That simply means that all doctrine and beliefs must be supported by scripture. It doesn’t say that sources can’t be used to attempt to explain what scripture is saying. It’s just that whatever they teach must be supported by scripture. Actually Paul gave a great explanation of Sola Scriptura.
“They searched the scriptures daily to see if these things be true”. If a teaching cannot be found or supported in scripture it is not to be taken as God’s word for doctrine or dogma.