Classical material not listed by Torah Temimah under this passuk (EXTRA).
Core Text — EXTRA
לָמָּה הָיָה הַקָּדוֹשׁ בָּרוּךְ הוּא נוֹתֵן זְמַן לַמַּכּוֹת, מָחָר, וְלֹא הָיָה מֵבִיא עֲלֵיהֶן מִיָּד? כְּדֵי שֶׁיַּחְזְרוּ בָּהֶן וְיַעֲשׂוּ תְּשׁוּבָה.
English: Why did the Holy One, blessed be He, give time to the plagues — “tomorrow” — and not bring them at once? So that they might turn and repent.