So then every one of you This clause shows what is meant by the calculation of expenses, with which Christ enjoins his followers to begin: it is to lead them to consider that they must forsake all In vain do persons who are delighted with an easy, indolent life, and with exemption from the cross, undertake a profession of Christianity. Those persons are said to forsake all who prefer Christ so greatly, both to their own life, and to all the wishes of the flesh, that nothing deters them from the right course. It would be absurd to insist on a literal interpretation of the phrase, as if no man were a disciple of Christ, till he threw into the sea all that he possessed, divorced his wife, and bade farewell to his children. Such idle dreams led foolish people to adopt a monastic life, as if those who intend to come to Christ must leave off humanity. Yet no man truly forsakes all that he possesses till he is prepared at every instant to leave all, gives himself free and unconstrained to the Lord, and, rising above every hindrance, pursues his calling. Thus the true self-denial which the Lord demands from his followers does not consist so much in outward conduct as in the affections; so that every one must employ the time which is passing over him without allowing the objects which he directs by his hand to hold a place in his heart.

Whosoever he be of you - This seems to be addressed particularly to those who were then, and who were to be, preachers of his Gospel; and who were to travel over all countries, publishing salvation to a lost world.

So likewise whosoever he be of you,.... Let him be ever so forward to follow me, to make a profession of me and of my Gospel, and to become a disciple of mine:
that forsaketh not all that he hath; when called to it, relations, friends, possessions, estates, and what not, which is an explanation of Luke 14:26
he cannot be my disciple; he is not in fact one, and is not worthy to be called one.

So - Like this man, who, being afraid to face his enemy, sends to make peace with him, every one who forsaketh not all that he hath - By withdrawing his affections from all the creatures; By enjoying them only in and for God, only in such a measure and manner as leads to him; By hating them all, in the sense above mentioned, cannot be my disciple - But will surely desist from building that tower, neither can he persevere in fighting the good fight of faith.