The presence of horsemen among the Egyptians is clearly indicated by the writings of Diodorus of Sicily, and as noted in Isaiah 31:1, there is a difference made between chariots and horsemen. Evidence of riding can be found in the papyri, but horsemen as depicted on ancient monuments have yet to be discovered. The Egyptians managed to catch up with the rear guard of the Israelites, which was stationed at Pi-Gahiroth near Baal-tsephon. Although the distance from Ajirud to Suez is approximately three miles, it’s important to consider that a vast population would have created a considerable encampment in the Suez valley. It is likely that the rear guard withdrew to join the main body of the Israelites, at which point the pillar of the Lord (verse 20) positioned itself between His people and the Egyptians.