Thematic Bible: Passover first commemorated

Jehovah spoke to Moses in the Desert of Sinai in the first month of the second year after the Israelites left Egypt. He said: The Israelites should celebrate the Passover at the same time every year. You must celebrate it on the fourteenth day of this month at dusk. Follow all the rules and regulations for the celebration of the Passover. read more.
So Moses told the Israelites to celebrate the Passover. They celebrated it on the fourteenth day of the first month at dusk while they were in the Desert of Sinai. The Israelites did everything as Jehovah commanded Moses.