How much time passed between the original Passover in Egypt and the Passover at Gilgal?
The interval was forty years to the day. Israel encamped at Gilgal and kept the Passover on the fourteenth day of the month at evening in the plains of Jericho, exactly forty years after the Passover celebrated that night in Egypt.
Les explains that after Israel encamped in Gilgal and kept the Passover on the fourteenth day of the month at evening in the plains of Jericho, this Passover was marked as forty years to the day from the Passover they celebrated that night in Egypt. The context places this after the circumcision at Gilgal, where the Lord said He had rolled away the reproach of Egypt, preparing the nation spiritually before the physical battles ahead.