In the book of Kings it is merely remarked in general, that the hostile relationship between Jeroboam and Rehoboam continued during his whole life, and that between Abijah and Jeroboam there was war (2Ch 13:6 and 2Ch 13:7); but not one of his enterprises is recounted, and only his attitude towards the Lord is exactly characterized. In our chapter, on the contrary, we have a vivid and circumstantial narrative of the commencement, course, and results of a great war against Jeroboam, in which Abijah, with the help of the Lord, inflicted a crushing defeat on the great army of the Israelites, and conquered several cities.
2Ch 13:1-2
The commencement and duration of the reign, as in 1Ki 15:1-2. Abijah’s mother is here (2Ch 13:2) called Michaiah instead of Maachah, as in 2Ch 11:20 and 1Ki 15:2, but it can hardly be a second name which Maachah had received for some unknown reason; probably מיכיהו is a mere orthographical error for מעכה. She is here called, not the daughter = granddaughter of Abishalom, but after her father, the daughter of Uriel of Gibeah; see on 2Ch 11:20.The War between Abijah and Jeroboam. - היתה מלחמה, war arose, broke out.