Num Numbers, chapter Book of Numbers, chapter 33
And they journeyed from Rameses in the first month, on the fifteenth day of the first month; on the morrow after the passover the children of Israel went out with a high hand in the sight of all the Egyptians, while the Egyptians were burying them that the LORD had smitten among them, even all their first-born; upon their gods also the LORD executed judgments.