Second Council of Nicaea, Canon VI

Concerning the holding of a local Synod at the time appointed.

Since there is a canon which says, twice a year in each province, the canonical enquiries shall be made in the gatherings of the bishops; but because of the inconveniences which those who thus came together had to undergo in travelling, the holy fathers of the Sixth Council decreed that once each year, without regard to place or excuse which might be urged, a council should be held and the things which are amiss corrected.  This canon we now renew.  And if any prince be found hindering this being carried out, let him be excommunicated.  But if any of the metropolitans shall take no care that this be done, he being free from constraint or fear or other reasonable excuse, let him be subjected to the canonical penalties.  While the council is engaged in considering the canons or matters which have regard to the Gospel, it behoves the assembled Bishops, with all attention and grave thought to guard the divine and life-giving commandments of God, for in keeping of them there is great reward; because our lamp is the commandment, and our light is the law, and trial and discipline are the way of life, and the commandment of the Lord shining afar giveth light to the eyes.  It is not permitted to a metropolitan to demand any of those things which the bishops bring with them, whether it be a horse or any other gift.  If he be convicted of doing anything of this sort, he shall restore fourfold.

Translation: Henry R. Percival, The Seven Ecumenical Councils, NPNF II.14 (1900), via CCEL.