וַיְהִ֡י לְעֵת֩ תְּשׁוּבַ֨ת הַשָּׁנָ֜ה לְעֵ֣ת ׀ צֵ֣את הַמְּלָכִ֗ים וַיִּנְהַ֣ג יוֹאָב֩ אֶת־חֵ֨יל הַצָּבָ֜א וַיַּשְׁחֵ֣ת ׀ אֶת־אֶ֣רֶץ בְּנֵֽי־עַמּ֗וֹן וַיָּבֹא֙ וַיָּ֣צַר אֶת־רַבָּ֔ה וְדָוִ֖יד יֹשֵׁ֣ב בִּירֽוּשָׁלִָ֑ם וַיַּ֥ךְ יוֹאָ֛ב אֶת־רַבָּ֖ה וַיֶּֽהֶרְסֶֽהָ׃
And it came to pass, at the time of the return of the year, at the time when kings go out to battle, that Joab led forth the power of the army, and wasted the country of the children of Ammon, and came and besieged Rabbah. But David tarried at Jerusalem. And Joab smote Rabbah, and overthrew it.
Midrash Tehillim
"Desires of the humble, You have heard, O Lord." Rabbi Levi said in the name of Rabbi Joshua, "This refers to Moses, who was called humble. When the Lord said to him (Leviticus 16:2), 'Speak to your brother Aaron, that he should not come at all times into the Holy Place,' Moses began to grieve. He said to himself, 'I am like nothing, for my brother is not permitted to enter the Holy Place, and I am even less worthy.' But then he remembered that there is a time for everything: a time for an hour, a time for a day, a time for a year, a time for twelve years, and a time for seventy years. There is a time for an hour, as it says (Leviticus 16:2), 'that he should not come at all times.' There is a time for a day, as it says (Ezekiel 4:11), 'You shall drink water by measure, a sixth of a hin.' There is a time for a year, as it says (1 Chronicles 20:1), 'It happened at the turn of the year.' For twelve years, as it says (Psalms 105:19), 'Until the time that his word came to pass.' For seventy years, as it says (Jeremiah 25:11), 'For Babylon will serve seventy years.' And there is a time for eternity, as it says (Psalms 4:8), 'You have put joy in my heart, more than when their corn and wine increased.' The Lord said to him, 'It is not as you think, that I enter whenever I want, but only at a designated time.' Moses then began to recite (Psalms 10:17), 'Desires of the humble, You have heard, O Lord; You will strengthen their heart, You will incline Your ear.'"...