Why were the Canaanites afraid and fainting because of Israel?
The inhabitants of the land were afraid and fainting because they had heard how the Lord dried up the water of the Red Sea for Israel when they came out of Egypt. Israel's terror had fallen upon them, and all the inhabitants of the land faint because of them.
Les teaches that Rahab's confession of faith was not much, but it was enough for her to become a Gentile believer. She told the spies, "I know that the Lord hath given you the land, and that your terror is fallen upon us, and that all the inhabitants of the land faint because of you." The reason she gave was, "For we have heard how the Lord, Jehovah, dried up the water of the Red Sea when you came out of Egypt." Les points out that this happened forty years earlier, and they had not forgotten. The king of Jericho was also shaking in his boots. So the fear and fainting of the land's inhabitants came from hearing what God had done for Israel at the Red Sea, not merely from Israel's presence.
For we have heard how the LORD dried up the water of the Red sea for you, when ye came out of Egypt; and what ye did unto the two kings of the Amorites, that were on the other side Jordan, Sihon and Og, whom ye utterly destroyed.