Luke 9:62

To put one's hand to the plough, is also, (as it were by a certain sharp instrument,) by the wood and iron of our Lord's passion, to wear away the hardness of our heart, and to open it to bring forth the fruits of good works. But if any one, having begun to exercise this, delights to look back with Lot's wife to the things which he had left, he is deprived of the gift of the kingdom to come.

(Nilus Monac.) For the frequent looking upon the things which we have forsaken, through the force of habit draws us back to our past way of life. For practice has great power to retain to itself. Is not habit generated of use, and nature of habit? But to get rid of or change nature is difficult; for although when compelled it for a while turns aside, it very rapidly returns to itself.

(de Con. Ev. l. ii. c. 23.) Our Lord spoke this to the man to whom He had said, Follow me. But another disciple put himself forward, to whom no one had spoken any thing, saying, I will follow thee, O Lord; but let me first go and bid them farewell who are at home, lest perchance they look for me as they are wont. (Serm. 100.) As if he said to him, The East calls thee, and thou turnest to the West.

Now this promise is worthy of our admiration and full of all praise, but to bid farewell to those who are at home, to get leave from them, shows that he was still somehow divided from the Lord, in that he had not yet resolved, to make this venture with his whole heart. For to wish to consult relations who would not agree to his proposal betokens one somewhat wavering. Wherefore our Lord condemns this, saying, No man, having put his hand to the plough, and looking back, is fit for the kingdom of God. He puts his hand to the plough who is ambitious to follow, yet looks back again who seeks an excuse for delay in returning home, and consulting with his friends.