שמואל ב, פרק י״א, פסוק א׳

The military campaign against the Ammonites remains unresolved, pausing only for the winter before resuming at a highly specific and meaningful time of year. Exactly one year has passed, marking the return of the sun to the precise point when kings traditionally set out for battle the previous year [מצודת דוד, רד״ק, אברבנאל, ביאור שטיינזלץ]. This period, falling in the spring and early summer, signals that the cold and rains have finally passed. The choice of season is highly practical: the land is now abundant with grain, grass, and fruit, allowing both the soldiers and their horses to easily find food in the fields to sustain themselves during the long journey [רש״י, רלב״ג, רד״ק, אברבנאל].

David dispatches his army commander Joab, along with the military leaders and the entire Israelite army, to launch a heavy offensive. They inflict massive devastation upon the enemy and place the capital city of Rabbah under a prolonged siege [מצודת ציון, ביאור שטיינזלץ, מלבי״ם].

Against the backdrop of this massive conflict, a sharp contrast emerges in the king's behavior. While the army is deployed, David remains behind in Jerusalem. The specific mention of the season and the sheer scale of the war serves to highlight his glaring absence. This is the proper time for battle, a major campaign where a king is expected to march at the head of his troops. David is neither tired nor weakened from past conflicts, yet he chooses to stay home, avoiding participation in God's war and failing to support his men at the front. This period of idle sitting in the capital, precisely when he should have been out on the battlefield, is what ultimately sets the stage for a tragic chain of events and the sin with Bathsheba [מלבי״ם, אברבנאל].