According to Jewish tradition, there was a group of Ephraimites who attempted to leave Egypt prematurely, before the time of the Exodus, and were killed as a result:

The Midrash relates that some descendants of Ephraim miscalculated the end of the 400 years of slavery that God had prophesied to Abraham. They left Egypt 30 years too early, without waiting for Moses to lead them3.

This group of Ephraimites armed themselves and marched out of Egypt toward Canaan. However, when they reached the land of the Philistines near Gath, they engaged in battle and were slaughtered3.

The Midrash states that 300,000 Ephraimites were killed in this failed attempt to leave Egypt early5. Their bones were said to be left scattered along the road as a warning13.

This tragedy is seen as the reason why God later led the Israelites on a longer route out of Egypt during the Exodus, to avoid having them see the bones of their brethren and become disheartened5.

Some rabbis have suggested that these bones of the Ephraimites were the same dry bones that Ezekiel saw in his vision, though this is not universally accepted13.

This story serves as a cautionary tale in Jewish tradition about the dangers of trying to force God's redemption before its proper time, rather than waiting patiently for divine deliverance35.