וַיֹּ֣אמֶר מֹשֶׁ֗ה הִנֵּ֨ה אָנֹכִ֜י יוֹצֵ֤א מֵֽעִמָּךְ֙ וְהַעְתַּרְתִּ֣י אֶל־יְהוָ֔ה וְסָ֣ר הֶעָרֹ֗ב מִפַּרְעֹ֛ה מֵעֲבָדָ֥יו וּמֵעַמּ֖וֹ מָחָ֑ר רַ֗ק אַל־יֹסֵ֤ף פַּרְעֹה֙ הָתֵ֔ל לְבִלְתִּי֙ שַׁלַּ֣ח אֶת־הָעָ֔ם לִזְבֹּ֖חַ לַֽיהוָֽה׃
Moïse répondit: "Sitôt que je t’aurai quitté, je vais intercéder auprès de l’Éternel et les animaux malfaisants se retireront de Pharaon, de ses serviteurs et de son peuple, dès demain. Du moins, que Pharaon cesse de se jouer de nous, en ne laissant pas le peuple partir pour sacrifier à l’Éternel."
Ramban
AS SOON AS I AM GONE OUT OF THE CITY, I WILL SPREAD FORTH MY HANDS UNTO THE ETERNAL. In line with the plain meaning of Scripture, it is possible to say that [on other occasions] Moses prayed in his house, [which was within the city]. However, this time He saw fit that his hands be spread heavenward so that the thunders and the hail cease immediately, and that was impossible to be done in the city [because it was replete with idols]. Hence he said, As soon as I am gone out of the city. And so it is said further on, And Moses went out of the city from Pharaoh, and spread forth his hands.222Verse 33. But at first, [i.e., during the plague of swarms], Moses said to Pharaoh, Behold, I go out from thee, and I will entreat the Eternal,223Above, 8:25. [for as soon as he left the palace he went to his house in the city and prayed].
But our Rabbis have said224Mechilta Introduction, and quoted further on (12:1) by Rashi. that Moses “did not pray within the city because it was full of idols, and all the more He did not converse with him except outside the city.” If so, we must say that since Pharaoh now pleaded with Moses that he remove the hail immediately,225Verse 28. Moses found it necessary to explain to him that he must go out of the city first and after that he will spread forth his hands to the Eternal, and He will remove it on account of his prayer. This is the true explanation.
But our Rabbis have said224Mechilta Introduction, and quoted further on (12:1) by Rashi. that Moses “did not pray within the city because it was full of idols, and all the more He did not converse with him except outside the city.” If so, we must say that since Pharaoh now pleaded with Moses that he remove the hail immediately,225Verse 28. Moses found it necessary to explain to him that he must go out of the city first and after that he will spread forth his hands to the Eternal, and He will remove it on account of his prayer. This is the true explanation.