Tradition
St. John Chrysostom
Homilies on the Statues
Homily 3
On the departure of Flavian, Bishop of Antioch, who had gone on an embassy to the Emperor Theodosius, on behalf of the city. Of the dignity of the Priesthood. What is true fasting. Slander worse than devouring the human body. And finally of those who had been put to death on account of the sedition; and against those who complained that many innocent persons were apprehended.
Source: Homilies on the Statues (New Advent)