And this He says not of lunatics in particular, but of the whole class of daemons. For fast endues with great wisdom, makes a man as an Angel from heaven, and beats down the unseen powers of evil. But there is need of prayer as even still more important. And who prays as he ought, and fasts, had need of little more, and so is not covetous, but ready to almsgiving. For he who fasts, is light and active, and prays wakefully, and quenches his evil lusts, makes God propitious, and humbles his proud stomach. And he who prays with his fasting, has two wings, lighter than the winds themselves. For he is not heavy and wandering in his prayers, (as is the case with many,) but his zeal is as the warmth of fire, and his constancy as the firmness of the earth. Such an one is most able to contend with daemons, for there is nothing more powerful than a man who prays properly.
But if your health be too weak for strict fast, yet is it not for prayer, and if you cannot fast, you can abstain from indulgences. And this is not a little, and not very different from fast.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).