Another interpretation: All the voices [thunders] are yours - "and there were thunders and lightnings" (Exodus 19:16); and the rains come in your merit - "at the sound of His giving a multitude of waters" (Jeremiah 10:13). If you chatter idly with your voice [instead of using it for Torah and prayer], the hands are the hands of Esau. And so it says, "Is the LORD among us" (Exodus 17:7) - immediately "and Amalek came" (Exodus 17:8).
All Thunder and Rain Are Given for the Sake of Jacob
Yalkut Shimoni on Torah 115:7
דָּבָר אַחֵר כָּל הַקּוֹלוֹת שֶׁלְּךָ "וַיְהִי קוֹלוֹת וּבְרָקִים", וְהַגְּשָׁמִים בִּזְכוּתְךָ (ירמיה י, יג) "לְקוֹל תִּתּוֹ הֲמוֹן מַיִם" אִם אַתָּה מְפַטֵּט בְּקוֹלְךָ הַיָּדַיִם יְדֵי עֵשָׂו. וְכֵן הוּא אוֹמֵר (שמות יז, ז) "הֲיֵשׁ ה' בְּקִרְבֵּנוּ" מִיָּד "וַיָּבֹא עֲמָלֵק".