Tradition
St. Benedict of Nursia
The Rule of St. Benedict
Chapter LI. Of the Brethren Who Do Not Go Very Far Away
CHAPTER LI
Of the Brethren Who Do Not Go Very Far Away
A brother who is sent out on any business and is expected to return to the monastery the same day, may not presume to eat outside, even though he be urgently requested to do so, unless, indeed, it is commanded him by his Abbot. If he act otherwise, let him be excommunicated.
Source: The Rule of St. Benedict (CCEL)