The plague of the frogs God brought down upon the Egyptians, "because," He said, "the frogs, which sometimes inhabit the water, shall take vengeance upon the Egyptians for having desired to destroy the nation destined to be the bearers of the Torah, and the Torah is likened unto water."
God sent vermin upon them, saying, "Let the lice made of the dust of the earth take vengeance upon the Egyptians for having desired to destroy the nation whose seed is like unto the dust of the earth."
Hordes of beasts, lions and wolves and swarms of serpents, came down upon them, "because," God said, "these animals shall take vengeance upon the Egyptians for having desired to destroy the nation that is likened unto lions, wolves, and serpents."