Every newborn son shall be thrown into the Nile
Rabbi Yohanan said:
What did the reserved and modest women of Israel do? They took their sons and put them in burrows, and the evil Egyptians took their small sons and put them into the house of Israel and pinched them and they cried, and the child of Israel would hear that his friend was crying – and cried with him, and the Egyptians would take them and throw them into the Nile.
When the Holy One Blessed be He wanted to drown the Egyptians in the sea, Azeh a minister in Egypt bowed down to the Holy One Blessed be He and said: Master of the Universe, have mercy on us. Why do you want to drown my son? Immediately the Holy One Blessed Be He convened all the followers of Heaven and said to them: Be the judges between me and between Azeh the minister of Egypt. The judges started to teach the Defence about Egypt.
As Michael saw this, he hinted to Gabriel and flew to Egypt in one flight and released Lavana from the mortar and one baby with her who were submerged in the building, in which he stood before the Holy One Blessed Be He and said:
G-d of the Universe, thus you have enslaved your sons! The Holy One Blessed Be He immediately replied. If so they shall drown in the sea. At the same time the guardian angels wished to sing to the Holy One Blessed Be He, the Holy One Blessed Be He said to them “the people I have made are drowning in the sea and you want to sing to me! (Sanhedrin 39)
As a result of four things Israel was redeemed from Egypt: that they did not change their names, and they did not change their language, they did not disclose their mystery and they did not cancel the circumcision.(Yalkut Shimoni)