From the Gerontikon:
A brother fell to temptation; that is, to sin. So great was the sorrow that he suffered, that he abandoned his monastic rule. And though he wanted in principle to repent, he was impeded from so doing by his sorrow, saying within himself: "How can I restore myself to what I was before?" Being thus remiss and negligent, he did not have the power to take up his monastic work.
So, he visited an Elder and confessed all that had befallen him.
The Elder, on listening to the matters which were tormenting the monk, related the following example to him in the form of an instructive parable:
A man, he began by saying, had a field. On account of his neglect of it, it became fallow and was overrun by weeds and brambles. After some time, this man thought about attending to his field and cultivating it. So, he ordered his son to clean up the field; but as soon as he saw that it was full of thorns, he was discouraged and said to himself: "I would never be able to uproot all that and to clean this field." So he lay down and went to sleep.
After a bit, he awakened and, gazing again on the vast number of brambles, became depressed by it all and lay on the ground - sometimes sleeping and sometimes rolling over from one side, the way a door swings on its hinge, as in the proverb: "As the door turneth upon its hinges, so doth the slothful upon his bed. The slothful hideth his hand in his bosom; it grieveth him to bring it again to his mouth" (Proverbs 26:14-16). He spent several days thusly, without working and inactive.
In the meantime, his father came along to check what he had done to the field. Finding his son idle and indecisive, he said to him:
"Why have you done nothing up to now, my child?"
The son answered:
"Father, as soon as I started to work and saw this mass of wild weeds and brambles, I lost my desire to work, lay down, and fell asleep. And so right up to today I have still done nothing."
"Do not worry, my son," the father replied, "every day you can clear an area the width of your bed, and thus your work will progress without inactivity crushing you."
Indeed, the son followed his father's advice and in a short time had cleaned the field of brambles and weeds.
"And in this way, my brother, you can work little by little, without risking the danger of being negligent. And God, seeing your desire to work, will restore you to your former rank."
The monk carefully listened to these suggestions, persisted with patience, and applied the directions of the Elder.
And indeed, by the Grace of God, he attained to the peace which he had sought.
From The Evergetinos (Volume 1 of the First Book), Center for Traditionalist Orthodox Studies, pp. 57-58.