"Ever consider that Paul wasn't referencing his own letters to the congregations? And he certainly wasn't referring to the Gospels which hadn't even been written yet. Anybody else ever notice this?"
Of course he is referring to the law and the prophets and not anything post Jesus. The same goes for 2 Tim 3:16 'all scripture is inspired'. Paul was inspired in the sense that he got the idea from past writings, but they were his interpretation of them.