The indicating of the hour for the Work of God by day and by night shall be the business of the abbot. Let him either do it himself or entrust the duty to such a careful brother that everything may be fulfilled at its proper time. The intoning of psalms and antiphons shall be done by those who are appointed for it, in their order after the abbot. But let no one presume to sing or read, unless he can fulfil the office to the edification of his hearers. Let it be done with humility, gravity and reverence, and by him whom the abbot has appointed.