HaShem told Moshe, "Here is what to do. Each of the extra first-born sons should pay five shekels. This money will free them from service, and will be given to Aharon and his sons."
Moshe thought, "That's fine, but what if I tell a first-born to pay his five shekels, and he refuses, saying that he is one of the first-born who is being replaced by a Levi?" Then Moshe had an idea. He made a lottery! Here's how it worked.
He prepared 22,273 slips of paper. On 22,000 of them he wrote "Levi," and on the remaining 273 he wrote "five shekels." Each first-born would draw a lot, and if he chose one that said "five shekels," he had to pay.
Why did Moshe go through all the trouble to make thousands and thousands of little papers? Can you imagine how long it must have taken to write them all out by hand? (The photocopy machine would not be invented for a few thousand years...) He did it because it was the only way to decide fairly who would pay. This way, no one would fight, and there would be peace among the people.
