Matthew Poole and continuators on 2 Samuel 11:1

AND it came to pass, that after the year was expired at the time when kings go forth to battel that David sent Joab and his servants with him, and all Israel; and they destroyed the children of Ammon, and besieged Rabbah , but David tarried still at Jerusalem.

Which is, when the ground is fit for the March of Soldiers, and brings forth Provision for Man and Beast.

These words are to be understood here, as Gen. 10. 11. and 14. 8.

The Chief and Royal City of the Ammonites, Deut. 3. 11.

a When that year ended, and the next begun, which was in the Spring-time, Exod. 12. 2.

Marginal references: Heb. at the return of the year.; 1 Chron. 20. 1.