Halakhah do Powtórzonego Prawa 26:6

"And the Egyptians did bad to us and afflicted us and put upon us hard work" (Deuteronomy 26:6). "And the Egyptians did bad to us" - as it is stated (Exodus 1:10), "Let us be wise towards him, lest he multiply and it will be that when war is called, he too will join with our enemies and fight against us and go up from the land."