For. — And, i.e., so.
Pekah... slew in Judah an hundred... in one day. — Details of what is generally stated in the last sentence of 2 Chronicles 28:5. The totals of slain and of captives (2 Chronicles 28:8) are both round numbers. The figures 120,000, if accurate, would show that about a third of the Jewish host (2 Chronicles 26:13) had fallen in the battle and pursuit. The ruthlessness of the foe is borne out by the words of the prophet Oded in 2 Chronicles 28:9 : “Ye have slain them in a rage that reacheth up to heaven.” Isaiah 7:6 proves that the allies designed to break wholly the independence of Judah, by abolishing the Davidic monarchy, and setting up a Syrian vassal king.
In one day. — In one great engagement. Among the Hebrews and Arabs the word “day” often bears the special force of “day of battle;” e.g., “the day of Midian” (Isaiah 9:4).
Because they had forsaken. — 2 Chronicles 27:2. Moreover, the idolatrous example of Ahaz would be eagerly followed by large numbers of the people, whose average religious condition was far below the standard which the prophets of Jehovah demanded. The prophetical writings demonstrate this.