Chief Articles of Faith
Article XIV. Of Ecclesiastical Order
Page 15 of 31
Of Ecclesiastical Order they teach that no one should publicly teach in the Church or administer the Sacraments unless he be regularly called.
Philip Melanchthon, The Augsburg Confession (1530), in the translation of the Triglot Concordia (1921). Public domain. Text from Project Gutenberg (eBook #275).