וַיִּרְא֞וּ עַבְדֵ֣י הֲדַדְעֶ֗זֶר כִּ֤י נִגְּפוּ֙ לִפְנֵ֣י יִשְׂרָאֵ֔ל וַיַּשְׁלִ֥ימוּ עִם־דָּוִ֖יד וַיַּֽעַבְדֻ֑הוּ וְלֹא־אָבָ֣ה אֲרָ֔ם לְהוֹשִׁ֥יעַ אֶת־בְּנֵי־עַמּ֖וֹן עֽוֹד׃ (פ)
And when the servants of Hadarezer saw that they were put to the worse before Israel, they made peace with David, and served him; neither would the Arameans help the children of Ammon any more.
Read midrashic interpretation of I Chronicles 19:19: and classical rabbinic exegesis.