On the Sunday that falls from the 13th to the 19th of the present month, we chant the Service to the 630 Holy and God-bearing Fathers who came together for the 4th Ecumenical Council who assembled in Chalcedon in 451, to condemn Eutyches, who taught that there was only one nature, the divine, in Christ after the Incarnation, and Dioscorus, Patriarch of Alexandria, who illegally received Eutyches back into communion and deposed Saint Flavian, Patriarch of Constantinople, who had excommunicated Eutyches.

In the Slavic tradition, on this Sunday, the Fathers of the first six Ecumenical Councils are all commemorated.

Saint Aquila, who was from Pontus of Asia Minor, was a Jew by race and a tent-maker by trade. In the year 52 he and his wife Priscilla were in Corinth when Saint Paul first came there. They gave him hospitality, and the Apostle remained with them for many days, himself working at the same trade as they (Acts 18:2-3). And having believed in Christ through Paul, they followed him from that time on, working together with him and suffering perils with him for the sake of the preaching of the Gospel, as he himself testifies concerning them in his Epistle to the Romans, saying: "Greet Priscilla and Aquila, my helpers in Christ Jesus: who have for my life laid down their own necks: unto whom not only I give thanks, but also all the churches of the nations" (Rom. 16:3-4). When and where they reposed is unknown.

Saint Joseph was the brother of Saint Theodore the Studite (see Nov. 11). He also is called Studite, especially when he is mentioned together with his brother. According to Codinus, both of them composed the canons of the Triodion during the reign of Leo the Armenian, while in the Church of Saint Romanus (see Nov. 18); he is not to be confused with Saint Joseph the Hymnographer (Apr. 3). When Saint Joseph became Archbishop of Thessalonica, he was exiled thrice because of his godly zeal for the holy icons, suffering many hardships, imprisonments in dark dungeons, hunger, thirst, and every tribulation, in the midst of which he departed unto eternal life in 833.