Leo the Great
Catena Aurea · Matthäusevangelium 6
But thou, when thou fastest, anoint thine head, and wash thy face; That thou appear not unto men to fast, but unto thy Father which is in secret: and thy Father, which seeth in secret, shall reward thee openly.
(Serm. in Quadr. vi. 2.) Fasting ought to be fulfilled not in abstinence of food only, but much more in cutting off vices. For when we submit ourselves to that discipline in order to withdraw that which is the nurse of carnal desires, there is no sort of good conscience more to be sought than that we should keep ourselves sober from unjust will, and abstinent from dishonourable action. This is an act of religion from which the sick are not excluded, seeing integrity of heart may be found in an infirm body.