Mark 4:12 Commentary - Whedon's Commentary on the Old and New Testaments
12. That Many learned men understand this that to mean so that. Others interpret it in order that. The former meaning indicates that parables were here used so that the effects described in this verse do really follow, but not with the divine intention that they should follow. The latter indicates that parables are used with the intention and purpose that such results should follow. Now the latter is the more ordinary sense, though not the necessary one, of the Greek word here rendered that. It here indicates that parables were used for the purpose that men who chose might remain blind. Not that their blindness is a primary purpose of the Almighty; but that blindness which is their choice may be accorded to them. These negative verbs not perceive and not understand, express intentional unintelligence. These men do not fall into passive ignorance, but they actively ignore. Lest This lest depends upon this ignoring. They ignore lest they should be converted. Obdurate sinners are sometimes afraid they will be converted. They fear that the truth will become so clearly truth that they cannot stand, and will in the trying moment yield to it. To prevent the evil use they would make of his truth Jesus wraps it in parables, and so accommodates their wish to his truth in order to avoid conversion. And their sins should be forgiven them Silly are these men who are so afraid of conversion. For what is the worst that would happen if they should be converted? Simply this: their sins would be forgiven, and they would be healed.
Consult other comments:
Mark 4:12 - Abbott's Illustrated New Testament
Mark 4:12 - The Greek Testament
Mark 4:12 - Calvin's Complete Commentary
Mark 4:12 - The Cambridge Bible for Schools and Colleges
Mark 4:12 - Companion Bible Notes, Appendices and Graphics
Mark 4:12 - Ellicott's Commentary for English Readers (Old and New Testaments)
Mark 4:12 - The Expositor’s Greek Testament by Robertson
Mark 4:12 - Garner-Howes Baptist Commentary
Mark 4:12 - John Gill's Exposition of the Entire Bible
Mark 4:12 - Gnomon of the New Testament
Mark 4:12 - Henry Alford's Greek Testament
Mark 4:12 - Biblical Illustrator Edited by Joseph S. Exell
Mark 4:12 - Robertson's Word Pictures in the New Testament
Mark 4:12 - A Popular Commentary on the New Testament
Mark 4:12 - Scofield Reference Bible Notes
Mark 4:12 - John Trapp's Complete Commentary (Old and New Testaments)
Mark 4:12 - The Treasury of Scripture Knowledge
Mark 4:12 - Whedon's Commentary on the Old and New Testaments
Whedon's Commentary on the Old and New Testaments

Daniel D. Whedon (1808-1885) was a prominent university professor, theologian, and author. He served as Professor of Ancient Languages at Wesleyan University in Connecticut; as Professor of Rhetoric at the University of Michigan; and as editor of the Methodist Quarterly Review from 1856 to1884. He authored numerous books including Commentary on the New Testament (New York: Carlton & Porter, 1860); Commentary on the Old Testament (New York: Nelson & Phillips, 1873); What is Arminianism? (Toronto: W. Briggs, 1879); and Essays, Reviews, and Discourses (New York: Phillips & Hunt, 1887).