Why the Egyptians Cried Woe When Pharaoh Let Israel Go

[Another interpretation of (Exodus 13:17): "And it came to pass (va-yehi), woe (wy), alas (hy), when Pharaoh let the people go."] Who cried "woe" (wy)? Resh Laqish said: The Egyptians cried "woe" (wy). To what is the matter comparable? To a physician who was in the district. When a person was injured, he would heal him; when one became sick, he would heal him. As soon as the physician left the district, the people of the district cried "woe" (wy). So it was when Israel was in Egypt: when the plague came upon the Egyptians, they would come to Moses and seek from him, and he would pray and heal the plague. When Israel went out of Egypt, at that moment the Egyptians said "woe" (wy) that Pharaoh has sent away the people. (Thus Exodus 13:17:) "And it came to pass (va-yehi), woe, when Pharaoh let the people go."