Why the Plague of Blood Struck Egypt First and Enriched Israel

HE REFUSES to let them go (Exodus 7:14). The Holy One, blessed be He, said: You refuse to send them away — by your life, you yourself will take each and every one of them by the hand and send them away! The Holy One, blessed be He, said to Moses: Go and bring upon him the plague of blood, "and you shall say to him: By this you shall know that I am the LORD" (Exodus 7:17). Why did He bring upon them the plague of blood first? Because Pharaoh and the Egyptians were worshiping the Nile. The Holy One, blessed be He, said to Moses: Go and strike their god before them. A common proverb says: "Strike the god, and the priests are put to shame" (its meaning: strike the false thing, and the priests will be ashamed). Therefore, "Behold, I will strike" (Exodus 7:17). See what is written: "upon their rivers" (Exodus 7:19). What is the meaning of "upon their rivers"? In every place where the waters were, they became blood. What is the meaning of "upon every pool of their waters" (Exodus 7:19)? Even what was in a jug became blood, and even what an Egyptian spat from his mouth became blood, as it is said: "And there shall be blood throughout all the land of Egypt" (Exodus 7:19). Rabbi Abin the Levite said: From the plague of blood Israel grew rich. How so? An Egyptian and an Israelite would be placed in one house, and the tub was full of water. The Egyptian would go to fill his jug from it, and it became blood, while the Israelite would go and drink water from it. The Egyptian would say, "Give me a little water in your hand," and he would give it to him — yet in the Egyptian's hand it was found to be blood. He would say to him, "Come, you and I, let us drink from the bowl," and the Israelite would drink water while the Egyptian drank blood. But when an Egyptian bought water from an Israelite for a price, he would drink water. Therefore, from the plague of blood Israel grew rich. And how long did the plague last upon them? Rabbi Judah and Rabbi Nehemiah: one said, for twenty-four days He warned them, and for seven days the plague was active upon them; and the other said, for seven days He warned them, and for twenty-four days it was active upon them.