The first of the ten plagues which G-d brought upon the Egyptians was "Dam" – the plague of blood, when G-d transformed the water in the river to blood. The Torah (Shemot 7:21) tells that as a result of this plague, all the fish in the river perished, causing the river to emit an offensive odor – "Va’yib’ash Ha’ye’or."

Rav Avrohom Schorr (contemporary), in his He’lekah Ve’ha’libub commentary to the Haggadah, cites the Sefas Emet (Rav Yehuda Aryeh Leib Alter of Ger, 1847-1905) as explaining the symbolic significance of this aspect of the plague. He writes that Beneh Yisrael sensed the "stench" of the land of Egypt, and recognized that they could no longer remain there. Earlier, when Moshe had conveyed to them G-d’s promise of redemption, they did not listen (6:9). But now they began realizing that they could not live in the decadent society in Egypt, and this is the meaning of "Va’yib’ash Ha’ye’or" – that they could no longer tolerate the "stench" of the impurity of the society among which they resided.

Rav Schorr added that fish are sometimes used as a symbol for physical desires. When Beneh Yisrael were in the desert and complained about the manna, longing to enjoy a variety of food, they reminisced about the fish that they were fed in Egypt ("Zacharnu Et Ha’daga" – Bamidbar 11:5), and the Sages explained that Beneh Yisrael on that occasion were also complaining about the Arayot (restrictions on intimate relationships). Fish, then, are a symbol for unrestrained indulgence in physical pleasures. As the plagues began, the "fish" of Egypt "died" in the eyes of Beneh Yisrael. The people began to realize that the pleasures which the society around them celebrated and pursued were just a mirage, that the joy they bring is temporary and not real, and that the decadent lifestyle the people around them lived was actually "malodorous," and not something to be embraced.

Rav Schorr explained on this basis the Midrash’s depiction of Beneh Yisrael and Egyptians drinking during the plague of blood. The Midrash relates that even if someone from Beneh Yisrael was drinking from the same cup as an Egyptian, he would receive water, but the Egyptian would receive blood. Rav Schorr writes that this symbolizes Beneh Yisrael’s changed perspective. They now viewed wanton physical indulgence differently than the Egyptians did; although they lived with the Egyptians, they had a very different outlook and a very different attitude.

The Yeser Ha’ra (evil inclination) seeks to mislead us by showing us a mirage. Forbidden activity appears to us as something valuable and important, as something we need to indulge in, which will bring us joy and satisfaction, when in truth, it is valueless and even harmful. We need to try to change our perspective, and regard forbidden pleasures as "malodorous," as something to reject and stay away from, so that we, like our ancestors in Egypt, will be worthy of our final redemption, speedily and in our times, Amen.