Beshalach - Rishon
The Scenic Route
When G-d led the Jews out of Egypt, He did not take them the shorter route, by way of the Philistines, because He knew that the sight of armed resistance would discourage the people. Instead, they took the "scenic route," to the Red Sea. (The Yam Suf, or "Sea of Reeds" may or may not actually be the same body of water we call the Red Sea today. For our purposes, let's just assume that it is.)
Moshe brought Yoseif's remains, to be buried in Israel, as Yoseif had made his brothers promise back in parshas Vayechi. G-d led the Jews on their trek with a pillar of cloud by day and a pillar of fire by night.
G-d directed Moshe to have the people set up camp opposite an idol called Baal Tz'fon (Master of the North). G-d had toppled the idols of Egypt, but Baal Tz'fon was still standing. This led Pharaoh to think that Baal Tz'fon had some actual power, a mistake that encouraged him into trying to recapture the Jews.
Sure enough, Pharaoh was remorseful that he let his work force go, so he assembled his army for pursuit.