Then, i.e. in this king’s days, when Jehoiada was dead, and Joash revolted from God; of which see 2Ch_24:17 &c. Gath; once a city of the Philistines, but taken by David, 1Ch_18:1, and now a part of the kingdom of Judah.
Set his face, i.e. directed his march, and led his forces. Or, undertook in good earnest. So the same phrase is used 2Ch_20:3Jer_21:10Eze_35:2.