Fasts indeed are to be imposed on a strong body; and those whom the rebellious flesh assails by the law of vices are to be wasted by continual fasting. The stiff flesh is to be subjugated by fasts, and so far to be restrained that it may lie subject to the rule of the mind and the commands of the soul, as a handmaid. And her whom continual infirmity has weakened, if you temper her with fasts, and she takes only as much as suffices for health, she will not sin. Yet judge her the better who, by the vigor of health, does not need the remedy of infirmity. Nor ought she who is healthy to be scandalized, if she who is infirm is fed more remissly or indulgently; but rather let her consider herself the better and holier for this, that she does not need the frail things which infirmity requires.
But she who under the pretext of infirmity merits something more lenient, let her be humble before the rest, and grieve that she cannot do what the others can; and let her not reckon her abstinence, relaxed for a time, to virtue, but to infirmity.