Deciding Moses and Aaron still weren’t suitably impressed by the sheer awesomeness of what God was about to do, he pulled them aside and explained, at great length, what was about to happen.

Further, he decided to give them a whole bunch of really specific rules about how they should celebrate how cool God’s next trick was going to be, thusly (paraphrased):

"The shit that's about to go down is going to be so incredibly awesome that you'll want to base your whole calendar around it. So, from now on, this month will be the first month of the year for you guys. I know you just bought that Hello Kitty calendar Aaron, but after what’s about to happen you'll be so impressed you'll rip that damn thing right off the wall. Also, since everyone else is going to have to buy new calendars too, it might be a good idea to start a calendar company. Just a suggestion.

"Anyway, on the 10th of this month, all of the Israelites need to go out and get themselves a lamb, one for each household. If two households are really small, they can share a lamb, but make sure everyone gets enough to eat. The lambs all have to be one year old males, and they can’t have any zits or anything. They can be either sheep or goats, but they'd better not be ugly.

"Keep the lambs around for 4 days, and then have everyone gather together and kill them all. Then, everyone should take their own lamb, take some of its blood, and smear it all over their door frames. That night, everyone gets to eat their lamb with flatbread. Oh, and also throw in some bitter herbs, because we don’t want it to be too tasty. If anything's left over, burn it, because as you all know I'm a big fan of burnt sheep. I shouldn't have to tell you people this, but make sure you’re fully clothed when you eat. Also, keep your staff in your hand (not that one you perverts) and eat quickly, because some serious shit is going to go down tonight, and you want to be done before it happens.

"You see, I (this is still God talking, remember) intend to kill the firstborn of every living thing here, because I'm tired of all these Egyptians worshipping their various gods instead of me. Yes, I know you probably thought I was just pissed because they wouldn't let you guys go, but really I’m much more upset at their stubborn refusal to acknowledge what a great guy I am. I'm going to go into every house and do some serious smiting. However, if I see blood all over the door frame, I'll skip that house, because I’ll know it belongs to someone who knows how to follow directions.

"Because I'm doing you a favor by not killing all of your firstborn, all of you need to hold a sort of memorial for this every year forever. Every year, you should celebrate Passover for 7 days. On the first day, take all the yeast out of your house, and don’t eat any bread that isn’t flat. If anyone eats leavened bread during those seven days, kick them out of the country. Yes, I'm serious. I once sold a guy's entire family line into slavery because he saw his father’s twig and berries. I don't fuck around.

"On the first and seventh day, you'll all go to synagogue. On those days, you won't do any work at all; you'll just sit there and eat unleavened bread all day long. In fact, for the whole seven days, you should do little else other than pigging out on flatbread. And no asking for yeast, or you're toast. No pun intended.

"For those marking this on your brand new calendars, this celebration will go from the 14th until the 21st of the first month of the year. You might want to go ahead and put that in your Blackberry. I'll wait.

"Got it? Great, moving on. Again, and I cannot stress this enough people: Absolutely no leavened bread in the land of Israel during these 7 days. I don’t care if some dude who's never even heard of Passover just happens to wander in with a loaf of Wonder Bread: Kick his ass out of the country pronto. Don't even try to fuck with me on this."

Having taken copious notes, Moses went to the elders of Israel to explain to them what God wanted all of them to do (paraphrased):

"Go out and kill some lambs, drain their blood into a bowl, and use some weeds (hyssop, to be specific) to smear the blood on your door frames. Then, when God comes around tonight like the anti-Santa Claus and starts killing everyone, he'll skip our houses.

"Also, we’re going to keep doing that same thing every year forever, even after we get to the land God's been promising us for the past several hundred years. And if your kids ask, just tell them it's because God didn't kill us while he was killing all of the Egyptians."

Suitably impressed by the plan, the Israelites spent a little time praying, and then went off to do what they were told.

That night at midnight, God came through and killed all the firstborn living creatures in Egypt, including everyone from Pharaoh's firstborn to the firstborn dung beetles. Pharaoh and the rest of the Egyptians woke up shortly thereafter, and started screaming and wailing and carrying on, and Pharaoh demanded the Israelites get the hell out of Dodge right away.

The Egyptians were so eager to get the Israelites the hell out of their country that the Israelites had to pack quickly, and didn't even have time to let their bread rise properly, which was just as well because God really had a thing against leavened bread during this particular time of year. On the way out, the Israelites went to "borrow" as much jewelry as they could from the Egyptians. The Egyptians were so desperate to get them out, they threw any valuables they could find at the Israelites just to get them to leave, so much so that all of the Egyptians ended up completely broke.

So the Israelites walked from Ramses to Succoth. They were about 600 thousand men (plus women and children), along with their various livestock. They stopped for a while to bake unleavened bread, because they hadn’t managed to bring any other food with them due to being in such a hurry and concentrating mostly on robbing the Egyptians blind. Thus did the Israelites' 430 year stay in Egypt come to an end.

God, deciding this chapter wasn't long enough already, told Moses and Aaron that only the children of Israel were allowed to eat the Passover feast. However, if an Israelite owned a slave, and had them circumcised, then that slave could eat. No hired hands or foreigners, though. So, to recap: slaves can eat, but if you pay them, they can’t.

Also, any given lamb can only be eaten in one house, and can't be carried around to other houses. And no breaking any lamb bones. Also, everyone in the congregation of Israel is required to partake.

If a stranger is staying with you, and they insist on being part of the Passover feast, they can do so, but only if they let you circumcise all of the men in their party. No uncircumcised man is allowed to join in. This, presumably, will keep most strangers from being too insistent about the matter.

Thus was the annual ritual of Passover started, and thus did the Israelites finally get to leave Egypt.