From Chapter 49 of the Rule of St. Benedict: The Observance of Lent
The life of a monk ought to be a continuous Lent. Since few, however, have the strength for this, we urge the entire community during these days of Lent to keep its manner of life most pure and to wash away in this holy season the negligences of other times. This we can do in a fitting manner by refusing to indulge evil habits and by devoting ourselves to prayer with tears, to reading, to compunction of heart and self-denial. During these days, therefore, we will add to the usual measure of our service something by way of private prayer and abstinence from food or drink, so that each of us will have something above the assigned measure to offer God of his own will with the joy of the Holy Spirit (1 Thess 1:6). In other words, let each one deny himself some food, drink, sleep, needless talking and idle jesting, and look forward to holy Easter with joy and spiritual longing. Everyone should, however, make known to the abbot what he intends to do, since it ought to be done with his prayer and approval. Whatever is undertaken without the permission of the spiritual father will be reckoned as presumption and vainglory, not deserving a reward. Therefore, everything must be done with the abbot's approval.