28 Here then shall these persons in their turn be in another more sublime degree of righteousness outdone, by them who shall so order themselves, that every day they shall betake them into the fields as unto pasture, and at what time they shall find it, pick up their meal, and having allayed their hunger, return. But plainly, on account of the keepers of the fields, how good were it, if the Lord should deign to bestow wings also, that the servants of God being found in other men's fields should not be taken up as thieves, but as starlings be scared off.
As things are, however, such an one will do all he can to be like a bird, which the fowler shall not be able to catch. But, lo, let all men allow this to the servants of God, that when they will they should go forth into their fields, and thence depart fearless and refreshed: as it was ordered to the people Israel by the law, that none should lay hands on a thief in his fields, unless he wanted to carry any thing away with him from thence; for if he laid hands on nothing but what he had eaten, they would let him go away free and unpunished.
Whence also when the disciples of the Lord plucked the ears of grain, the Jews calumniated them on the score of the sabbath rather than of theft. But how is one to manage about those times of year, at which food that can be taken on the spot is not found in the fields? Whoso shall attempt to take home with him any thing which by cooking he may prepare for himself, he shall, according to these persons' understanding of it, be accosted from the Gospel with, “Put it down; for this the birds do not.”
Source: On the Work of Monks (New Advent)