Therefore I implore your holiness to turn your back on the liars; to give heed to the Church's quiet and either to heal by salutary medicines them that are trying to destroy the doctrines of the truth, or, if they refuse to accept your treatment, to expel them from the fold, to the end that the sheep may be spared from contagion. I beg you to give me your customary salutation. That I have written you my true sentiments is proved by my works on the holy Scriptures and against the Arians and Eunomians.
I will in addition write yet a brief word. If any one refuses to confess the holy Virgin to be “Theotokos,” or calls our Lord Jesus Christ bare man, or divides into two sons Him who is one only begotten and first born of every creature, I pray that he may fall from hope in Christ, and let all the people say amen, amen.
Now that I have thus spoken, deign, my lord, to give me your sacred prayers, and to cheer me by a letter in reply telling me that your holiness has turned your back on my accusers.
I and my household salute all your brotherhood in piety in Christ.
Source: Letters (New Advent)