Then Moses told the Hebrews that God gave them the following instructions, and that it was crucial that they follow these orders to a T to avoid being smote along with the Egyptians. He told them that everyone needed to sacrifice a lamb at twilight and then smear its blood all over the lintels and doorposts of their houses. Also that night, everyone was to eat a feast of unleavened bread and bitter herbs and to burn whatever wasn’t eaten. After dinner everyone needed to be dressed, packed and ready to flee, because the orders from Pharaoh to drive them out would be shortly forthcoming.
Moses also told them that in the future, the Hebrews would always celebrate this holiday for a week, and hold the main feast on the tenth day of the first month of every year. In the future, Hebrews would not be allowed to eat or even possess any leaven during that whole week.
So all the people followed Moses orders, and at midnight, God smote all the Egyptian firstborn, from the cow in its byre to the Pharaoh’s son in his palace bed. Soon, mass confusion and the wailing of bereaved parents broke out, and in the midst of all this Pharaoh called Moses and Aaron to him and told them that the Hebrews needed to go. NOW. By morning. Any Hebrews found at the break of day would be summarily executed on the spot. So the Hebrews, who were packed and ready to go, quickly absconded with all that borrowed jewelry and clothing.
Morning light shown upon a horde of 600,000 Hebrew men, plus their women, children, animals, slaves and various disaffected Egyptians travelling northwest across the Egyptian desert. Here it claims that the Hebrews had been in Egypt 430 years and not the four generations it counted earlier.
On the way, God reminded Moses and Aaron of keeping Passover yearly and told them that in the future, only the circumcised would be allowed to keep it.