Then Moses called together all the elders of Israel and told them, “Go immediately and choose a lamb for each of your families, and kill the Passover lamb.
Observe it at the time required—in the evening after sunset on the fourteenth day of this month, and do so in accordance with its rules and regulations.”
So they kept the Passover in the Sinai desert, beginning in the evening after sunset on the fourteenth day of the first month. The Israelites followed all the instructions the Lord had given to Moses.