וַיֻּגַּ֗ד לְבֵ֤ית דָּוִד֙ לֵאמֹ֔ר נָ֥חָֽה אֲרָ֖ם עַל־אֶפְרָ֑יִם וַיָּ֤נַע לְבָבוֹ֙ וּלְבַ֣ב עַמּ֔וֹ כְּנ֥וֹעַ עֲצֵי־יַ֖עַר מִפְּנֵי־רֽוּחַ׃
And it was told the house of David, saying: ‘Aram is confederate with Ephraim.’ And his heart was moved, and the heart of his people, as the trees of the forest are moved with the wind.
Read midrashic interpretation of Isaiah 7:2: and classical rabbinic exegesis.