So Abijah slept with his fathers, and they buried him in the city of David: and Asa his son reigned in his stead. In his days the land was quiet ten years.
Quiet — There was no open war, but there were private hostilities between his and Baasha's subjects.
 And he built fenced cities in Judah: for the land had rest, and he had no war in those years; because the LORD had given him rest.
The land had rest — Those have rest indeed, to whom God gives rest; peace indeed, to whom Christ gives peace. We find by experience, it is good to seek the Lord. While we pursue the world, we meet with nothing but vexation.
 Therefore he said unto Judah, Let us build these cities, and make about them walls, and towers, gates, and bars, while the land is yet before us; because we have sought the LORD our God, we have sought him, and he hath given us rest on every side. So they built and prospered.
Before us — In our power.
 And there came out against them Zerah the Ethiopian with an host of a thousand thousand, and three hundred chariots; and came unto Mareshah.
Ethiopian — Or, the Arabian, as the Hebrew word Cush is commonly used: these being much nearer to Asa than the Ethiopians.
 And Asa cried unto the LORD his God, and said, LORD, it is nothing with thee to help, whether with many, or with them that have no power: help us, O LORD our God; for we rest on thee, and in thy name we go against this multitude. O LORD, thou art our God; let not man prevail against thee.
Let not man prevail — If he prevails against us, he prevails, as it were, against thee; because thou art our God. And we rest on thee, and go forth in thy name, which thou hast encouraged us to do.
 So the LORD smote the Ethiopians before Asa, and before Judah; and the Ethiopians fled.
Smote — With terror, and an unaccountable consternation.
 And they smote all the cities round about Gerar; for the fear of the LORD came upon them: and they spoiled all the cities; for there was exceeding much spoil in them.
Smote the cities — because they had joined, with Zerah in this war.