Nicene and Post-Nicene Fathers, Ser. II, Vol. XII:
The Letters and Sermons of Leo the Great.: To the Presbyters and Deacons of the Church of Alexandria.

Letter CLXXII.

To the Presbyters and Deacons of the Church of Alexandria.

(Inviting them to aid in confirming the peace of the Church, and in winning those who had given way to heresy.)