ישועתו יום אל מיום בשרו הארץ כל ‘לה שירו
Harav Saadya Gaon explained: Those who believe that the world is run by constellations and mazalos believe that there is no way to work today for the salvation of tomorrow, because the star that reigns that day has no control on the day that follows. Therefore, when wanting to describe the Kingship of Hashem in His world, Dovid Hamelech said: “Shiru L’Hashem,” Who rules everything and is the Master of time, and His salvation is not limited to this day or that day, but rather “from day to day is His salvation.”
For this reason, after the plague of frogs, Pharaoh asked Moshe to pray that day that the frogs should be removed the next day (Rashi Shemos 8:5). Why did Pharaoh delay the removal of the plague to the next day instead of asking that it should be removed immediately?
Pharaoh, who did not believe in Hashem’s Reign, and attributed the ways of the world to the power of the stars and the constellations, was sure that there was no way to pray today for a salvation to happen tomorrow. So he said to Moshe: If you want to prove to me that you are not operating by the power of the stars and the constellations, and you are coming with the Word of Hashem, Who rules everything, then pray today that the frogs should be taken away tomorrow. And to that Moshe replied (Shemos ibid 6): “As you say, in order that you should know that there is no other like Hashem, our G-d,” Who rules over everything, and His kingship is not limited to one day or another.
Ohr Olam [Rav Y.L. Margulies] p. 23b
