Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Councils of Ancyra, Gangra, Neocæsarea, Antioch and Laodicea, which Canons were Accepted and Received by the Ecumenical Synods.: The Synodal Letter.

p. 107 The Synodal Letter.

(Found in Labbe and Cossart, Concilia, Tom. II., col. 559.  It really is no part of the canons, but I have placed it here, because, as Labbe notes, “it is usually prefixed to the canons in the Greek.”)

The holy and most peaceful Synod which has been gathered together in Antioch from the provinces of Cœle-Syria, Phœnicia, Palestine, Arabia, Mesopotamia, Cilicia, and Isauria; 166 to our like-minded and holy fellow Ministers in every Province, health in the Lord.

The grace and truth of our Lord and Saviour Jesus Christ hath regarded the holy Church of the Antiochians, and, by joining it together with unity of mind and concord and the Spirit of Peace, hath likewise bettered many other things; and in them all this betterment is wrought by the assistance of the holy and peace-giving Spirit.  Wherefore, that which after much examination and investigation, was unanimously agreed upon by us bishops, who coming out of various Provinces have met together in Antioch, we have now brought to your knowledge; trusting in the grace of Christ and in the Holy Spirit of Peace, that ye also will agree with us and stand by us as far as in you lies, striving with us in prayers, and being even more united with us, following the Holy Spirit, uniting in our definitions, and decreeing the same things as we; ye, in the concord which proceedeth of the Holy Spirit, sealing and confirming what has been determined.

Now the Canons of the Church which have been settled are hereto appended.

Footnotes

Hefele thinks this list of provinces is probably an interpolation.  In the Latin version this letter is followed by the names of the bishops.