Midrash su Esodo 7:24

(Exod. 10:22:) AND THERE WAS THICK DARKNESS IN ALL THE LAND OF EGYPT FOR THREE DAYS. There were < actually > seven days of darkness over the Egyptians.¹⁰Tanh., Exod. 3:3; Exod. R. 14:3. For the first three days whoever was sitting and wanted to stand would stand, and whoever was standing and wanted to sit would sit. Then for the next three days whoever was sitting was unable to stand and whoever was {sitting} [standing] was unable to sit.¹¹Tanh., Exod. 3:3, and Exod. R. 14:3 explains how the two sets of three days are derived from Exod. 10:22–23. First THERE WAS A THICK DARKNESS IN ALL THE LAND OF EGYPT FOR THREE DAYS WHEN THEY COULD NOT SEE ONE ANOTHER. THEN FOR THREE DAYS NO ONE COULD GET UP FROM WHERE HE WAS. Here are six <days>. And which day was the seventh? The one of which it is stated (in Exod. 14:20): THUS THERE WAS THE CLOUD AND THE DARKNESS WHICH LIT UP THE NIGHT. The cloud was in Egypt; and while it gave light to Israel, it was darkened for Egypt, as stated (in Exod. 10:23): BUT ALL THE CHILDREN OF ISRAEL HAD LIGHT IN THEIR DWELLINGS. Now, Israel entered the houses of the Egyptians, and whatever the Egyptians had, Israel searched out and looked at <them>. So, when the Holy One said to Israel (in Exod. 3:22): BUT EACH WOMAN SHALL BORROW < OBJECTS OF SILVER, OBJECTS OF GOLD, AND CLOTHING > FROM HER NEIGHBOR AND FROM THE WOMAN WHO SOJOURNS IN HER HOUSE…, Israel entered in among the Egyptians. Then, when each and every one would say to his companion and neighbor: Lend me that object which you have, and when he would say: I do not have it, he would say: I know that you have it, and here it is in your chest. See, it is in such and such a place. I saw it in your hand. So he lent him that object. And how did Israel know this? It is simply that in those days of darkness they had entered their houses and seen their silver, their gold, and whatever objects they had. R. Abbin the Levite said: Also when the plague of blood came over the Egyptians,¹²Cf. above 2:14. the Nile was turned into blood, as stated (in Exod. 7:24): AND ALL THE EGYPTIANS DUG AROUND THE NILE FOR WATER TO DRINK, < BECAUSE THEY COULD NOT DRINK THE WATER OF THE NILE>. What did they do? They saw Israel filling its casks from the Nile. So they went after them and sought water to drink from them, but it became blood within their mouths. R. Abbin said: Whatever they bought from Israel for a price they drank as water. Since it is impossible for anyone to exist without water, they bought water from Israel and thereby enriched Israel. [So also here, when the plague of darkness came upon them, they were acquainted with the Egyptians' houses and thereby <the Egyptians > made Israel rich.]