That Matthew writes here “mourn,” where Mark and Luke write “fast,” shews that the Lord spake of that kind of fasting which pertains to humbling one’s self in chastisement; as in the following comparisons He may be supposed to have spoken of the other kind which pertains to the joy of a mind wrapt in spiritual thoughts, and therefore averted from the food of the body; shewing that those who are occupied about the body, and owing to this retain their former desires, are not fit for this kind of fasting.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: De Cons. Evan., ii, 27