Rabbi Shmuel bar Nachman said in the name of Rabbi Yonatan: What is meant by, “[The angel of God, who had been going ahead of the Israelite army now move and followed behind them. And the pillar of cloud shifted from in front of them and took up a place behind them. And it came between the army of the Egyptians and the army of Israel. Thus there was the cloud with the darkness, and it cast a spell upon the night,] so that the one could not come near the other all through the night” (Exodus 14:19-20).
In that hour [when the Israelites were crossing the Sea of Reeds,] the ministering angels wanted to sing a song of praise before God [Isaiah 6:3]. But God said to them: “My handiwork is drowning in the sea, and you want to sing a song before me?!”
The crossing of the Sea of Reeds was the culmination of the Exodus from Egypt. Only when the sea closed upon the pursuing Egyptians did the Israelites realize true freedom. It was naturally a time of great relief and celebration. In this passage, it is imagined that the angels wanted to sing a song of joy before God, proclaiming as they did in Isaiah, “Holy, holy, holy is Adonai-tz’vaot, the fullness of the earth is God’s glory.”
But God admonishes them not to rejoice because God’s handiwork, the Egyptians, were dying. Even though such death and destruction is necessary for the liberation of the Israelites to be successful (much as the 10 plagues are also necessary), we should not celebrate and rejoice at their suffering and destruction. It is one thing to celebrate our freedom, as we do each year at Pesach, but quite another thing to rejoice when others suffer. That is why, for example, that we spill a drop of wine —our symbol of joy— from our kiddush cup during the Passover Seder when we recite each of the ten plagues.
The cost of freedom is often high. If there were another way, with less suffering, then that would have been the path to freedom. We are certainly grateful that God redeemed us from Egyptian bondage, and our celebration focuses on this great delivery from servitude.