John 13:17

If ye know these things,.... The duties they owed to him, and one another; those kind offices of love and respect to each other; the humility, condescension, and brotherly love, which ought to be in them, and of which he had given them an example:

happy are ye if ye do them; for the bare theory, or a mere speculative knowledge of these things, is not sufficient; not he that knows and does not, but he that knows and does his master's will, is blessed; he is blessed with communion with his Lord, and shall hereafter enter into his joy, with "well done good and faithful servant". There is an happiness "in" doing well, and which follows "on" it, though not "for" it, in a way of merit; on the other hand, persons who know and do not, are very unhappy; the Jews have a saying a,

"twvel alv dmlhv, "he that learns but not to do", it would have been better for him, if he had never been created; and says R. Jochanan, he that learns but not to do, it would have been better for him if his secundine had been turned upon his face, and he had never come into the world.''

a Hieros. Beracot, fol. 3. 2.