וַיְהִי֩ לִתְשׁוּבַ֨ת הַשָּׁנָ֜ה לְעֵ֣ת ׀ צֵ֣את הַמַּלְאֿכִ֗ים וַיִּשְׁלַ֣ח דָּוִ֡ד אֶת־יוֹאָב֩ וְאֶת־עֲבָדָ֨יו עִמּ֜וֹ וְאֶת־כָּל־יִשְׂרָאֵ֗ל וַיַּשְׁחִ֙תוּ֙ אֶת־בְּנֵ֣י עַמּ֔וֹן וַיָּצֻ֖רוּ עַל־רַבָּ֑ה וְדָוִ֖ד יוֹשֵׁ֥ב בִּירוּשָׁלִָֽם׃ (ס)
Tendo decorrido um ano, no tempo em que os reis saem à guerra, Davi enviou Joabe, e com ele os seus servos e todo o Israel; e eles destruíram os amonitas, e sitiaram a Rabá. Porém Davi ficou em Jerusalem.
Rashi on II Samuel
At the time [of year] when kings go forth. There is a time of year when it is the practice that troops go forth, when the land is full of growth and the horses find produce in the field to eat.