Another interpretation of "You stretched out Your right hand" (Exodus 15:12): this teaches that the sea cast them onto the dry land and the dry land cast them back into the sea. The dry land said: If, when I received only the blood of Abel alone, it was said to me, "Cursed are you from the ground" (Genesis 4:11) ["Cursed are you from the ground"], now how can I receive the blood of all these multitudes? until the Holy One, blessed be He, swore to her that He would not bring her to judgment, as it is said, "You stretched out Your right hand" and "right hand" means nothing other than an oath, as it is said, "The LORD has sworn by His right hand" (Isaiah 62:8).
The Sea and the Dry Land Argue and God Swears an Oath
Yalkut Shimoni on Torah 251:2
דָּבָר אַחֵר נָטִיתָ יְמִינְךָ, מַגִּיד שֶׁהַיָּם זְרָקָן לַיַּבָּשָׁה וְיַבָּשָׁה זְרָקָתָן לַיָּם. אָמְרָה הַיַּבָּשָׁה, וּמָה אִם בְּשָׁעָה שֶׁלֹּא קִבַּלְתִּי אֶלָּא דָּמוֹ שֶׁל הֶבֶל יְחִידִי נֶאֱמַר לִי (וְעַתָּה אֲרוּרָה) (בראשית ד, יא) ["אָרוּר אָתָּה מִן] הָאַדֲמָה", וְעַכְשָׁיו הֵיאַךְ אֲנִי יְכוֹלָה לְקַבֵּל דָּמָן שֶׁל כָּל אֵלּוּ אוּכְלוּסִין. עַד שֶׁנִּשְׁבַּע לָהּ הַקָּדוֹשׁ בָּרוּךְ הוּא שֶׁאֵינָהּ מַעֲמִידָהּ בַּדִּין, שֶׁנֶּאֱמַר נָטִיתָ יְמִינְךָ וְאֵין יָמִין אֶלָּא שְׁבֻעָה, שֶׁנֶּאֱמַר "נִשְׁבַּע ה' בִּימִינוֹ".