During the 6th century AD, Isho'yahb I, Patriarch of the Church of the East, produced a code of law dealing with questions raised by Bishop Jacob of Darai in the Gulf. Perennial Church issues include priestly conducts, ecclesiastical rankings, and ordinations. Legal matters for the faithful concern wills, marriages, vows, lending at interest, and swearing. Most interesting are names of church architecture that the Code gives, including bema, diaconicon, and qestroma, terms that are still used today.