There was no accepted canon before that. Remember that different Jewish groups - whether in Israel or in Ctesiphon or in Egypt had different accepted prophet compilations.
He referenced Ecclesiasticus (Sirach)2:15-16, (Septuagint) or Sirach 2:18 (Confraternity).
I disagree. It sure looked like they knew what was or what wasn't God's word. Why else would Jesus preface his teachings with "it is written" if that held no recognition of Divine authority? When Jesus read from the scroll in the temple, did the religious leaders respect that He was reading from God's word? Leave aside the whole idea of a formally announced canon for a minute and think about what was already believed about the Law, the Prophets and the Psalms.
He referenced Ecclesiasticus (Sirach)2:15-16, (Septuagint) or Sirach 2:18 (Confraternity).
I don't see it.
Sirach 2:15-16
Those who fear the Lord disobey not his words; those who love him keep his ways. Those who fear the Lord seek to please him, those who love him are filled with his law.
This site https://turretinfan.wordpress.com/2011/03/17/did-jesus-quote-from-the-apocrypha/ shows some more presumed quotes from Jesus. But even if He did, can you demonstrate that Jesus meant it was Inspired writing?