No man, etc. - As ploughing requires an eye intent on the furrow to be made, and is marred the instant one turns about, so will they come short of salvation who prosecute the work of God with a distracted attention, a divided heart. Though the reference seems chiefly to ministers, the application is general. The expression “looking back” has a manifest reference to “Lot’s wife” (Gen 19:26; and see on Luk 17:32). It is not actual return to the world, but a reluctance to break with it. (Also see on Mat 8:21.)