וַיִּסְעוּ֙ מִפְּנֵ֣י הַֽחִירֹ֔ת וַיַּֽעַבְר֥וּ בְתוֹךְ־הַיָּ֖ם הַמִּדְבָּ֑רָה וַיֵּ֨לְכ֜וּ דֶּ֣רֶךְ שְׁלֹ֤שֶׁת יָמִים֙ בְּמִדְבַּ֣ר אֵתָ֔ם וַֽיַּחֲנ֖וּ בְּמָרָֽה׃
하히롯 앞에서 발행하여 바다 가운데로 지나 광야에 이르고 에담 광야로 삼 일 길쯤 들어가서 마라에 진 쳤고
Rabbeinu Bahya
ויסעו מפני החירות ויעברו בתוך הים המדברה, “they journeyed away from Pi Hachirot and they crossed the sea into the desert.” The Torah repeats that the people journeyed from Eylim and encamped by the Sea of Reeds to teach us that they returned to the side of the sea they had already passed previously.
Chizkuni
ויעברו בתוך הים המדברה, “they passed through the midst of the sea into the wilderness;” the same spirit (wind) that had helped them to enter the sea when coming from the desert on the other side, also helped them face the desert when emerging from the sea. (Tossaphot Erchin 15) This was the North wind that G-d had only activated in order to encourage the Egyptians to pursue the Israelites.