וַיֵּ֨ט מֹשֶׁ֣ה אֶת־מַטֵּהוּ֮ עַל־אֶ֣רֶץ מִצְרַיִם֒ וַֽיהוָ֗ה נִהַ֤ג ר֥וּחַ קָדִים֙ בָּאָ֔רֶץ כָּל־הַיּ֥וֹם הַה֖וּא וְכָל־הַלָּ֑יְלָה הַבֹּ֣קֶר הָיָ֔ה וְר֙וּחַ֙ הַקָּדִ֔ים נָשָׂ֖א אֶת־הָאַרְבֶּֽה׃
Моисей простер Свой жезл на землю Египетскую, и Господь навел восточный ветер на землю весь день и всю ночь; и когда было утро, восточный ветер принес саранчу.
Rashi
ורוח הקדים THE EAST WIND — It was an east wind that brought the locusts because that came (blew) from the direction opposite to it (to Egypt), since Egypt was in the south-west, relative to Palestine, as it is explained in another place (Numbers 34:3).
Alshekh
Moshe stretched out his rod. Hashem honored Moshe by saying that the locusts would come through the extension of Moshe’s hand (see v. 12) and Moshe reciprocated the honor by extending the rod of Hashem.
Chizkuni
רוח קדים, “an east wind.” It is called קדים, as this is where the sun begins its daily route; this is also why west is called אחור, “hindmost,” as this is where the sun completes its daily route.