Ahhhhh
400 AD
hmmmm
I think Christ Ascended and Paul died a bit before that.
So why is Luther's canon of Scripture more authoritative than that of the Christians who lived 1100 years closer to the time of Christ?
Regardless, of the roughly 300 Old Testament citations by Jesus and the Apostles in the New Testament, two-thirds are drawn from the Septuagint, which is the Catholic OT canon.
Septuagint Quotes in the New Testament.
Here's a more exhaustive history of the development of the canon of Scripture.