17. set his face--purpose steadfastly. Antiochus purpose was, however, turned from open assault to wile, by his war with the Romans in his endeavor to extend his kingdom to the limits it had under Seleucus Nicator.
      upright one--Jasher, or Jeshurun (De 32:15; Isa 44:2); the epithet applied by the Hebrews to their nation. It is here used not in praise; for in Da 11:14 (see on Da 11:14) they are called "robbers," or "men of violence, factious": it is the general designation of Israel, as having God for their God. Probably it is used to rebuke those who ought to have been God's "upright ones" for confederating with godless heathen in acts of violence (the contrast to the term in Da 11:14 favors this).
      thus shall he do--Instead of at once invading Ptolemy's country with his "whole strength," he prepares his way for doing so by the following plan: he gives to Ptolemy Epiphanes his daughter Cleopatra in marriage, promising Cœlo-Syria and Judea as a dowry, thus securing his neutrality in the war with Rome: he hoped through his daughter to obtain Syria, Cilicia, and Lycia, and even Egypt itself at last; but Cleopatra favored her husband rather than her father, and so defeated his scheme [JEROME]. "She shall not stand on his side."

JFB.