It is a thing plainly repugnant to the Word of God, and the custom of the primitive church, to have public prayer in the church, or to minister the Sacraments, in a tongue not understood by the people.
Article XXIV of the Episcopal doctrine is identical, but they add before it one regarding lawful ministers who may serve in the churches. Note that the Article is not explicit about what tongue they mean, but it is likely to be an objection to the Latin mass when that language is no longer spoken amongst the people. A modern view of the prohibition would also include “speaking in tongues” without an interpreter as found in some Pentecostal churches today. If anyone speaks in a tongue, it must be by two or at the most three, and each one in turn, and one is to interpret; but if there is no interpreter, he is to keep silent in church; and have him speak to himself and to God. (1 Cor 14:27-28, NASB) This suggests to me that speaking in a tongue not understood by the people would have been allowed in the primitive church if an interpretation followed.
XXIII. Of Ministering in the Congregation.
It is not lawful for any man to take upon him the office of public preaching, or ministering the Sacraments in the Congregation, before he be lawfully called, and sent to execute the same. And those we ought to judge lawfully called and sent, which be chosen and called to this work by men who have public authority given unto them in the Congregation, to call and send Ministers into the Lord’s vineyard.
Making a Difference in the World 