Behold my brothers, how much a fast can do, and in what manner the law commands us to fast. It is required that not only with the body should we fast, but with the soul. Now the soul is humbled when it does not follow wicked opinions, but feeds on becoming virtues. For virtues and vices are the food of the soul and it can eat either of these two meats, and incline to either of the two, according to its own will. If it is bent toward virtue, it will be nourished by virtues, by righteousness, by temperance, by meekness and by fortitude. Such was the case with our Lord, Who said, ‘My food is to do the will of My Father Who is in heaven’ (Jn.4:34). But if it is not thus with the soul, and it inclines downwards, it is then nourished by nothing but sin.