Charles Ellicott Commentary 2 Chronicles 15:6

"And they were broken in pieces, nation against nation, and city against city; for God did vex them with all adversity." — 2 Chronicles 15:6 (ASV)

And nation was destroyed of nation. — And they were crushed, nation by nation and city by city. The verb khathath occurs Isaiah 2:4 (“to beat”); but in its (intensive) passive form only here. Some manuscripts have the (intensive) active form, which is found elsewhere.

So Septuagint and Vulgate: “And nation shall fight against nation.” Nation is gôy, i.e., a community of kindred, such as a tribe or clan, rather than a merely political aggregate.

The allusion is to the old feuds and contentions between rival tribes, for example, between Ephraim and Gilead (Manasseh) (Judges 12:0), or between Benjamin and the other tribes (Judges 20:0). The verse vividly portrays an internecine strife, like that described in Isaiah 19:2: “And I will set the Egyptians against the Egyptians, and they shall fight every one against his brother, and every one against his neighbour; city against city, kingdom against kingdom;” or like that depicted by the same prophet (Isaiah 9:18–21): “No man shall spare his brother ... they shall eat every man the flesh of his own arm [i.e., of his natural ally]: Manasseh, Ephraim; and Ephraim, Manasseh; and they together shall be against Judah.”

Did vex them with all adversity. — Had confounded (or, discomfited) them with every kind of distress. (Compare to Zechariah 14:13: “A great confusion from the Lord.”)