"It was told to the king of Egypt that the people had fled, and the heart of Pharaoh and his servants became transformed regarding the people, and they said, 'What is this that we have done, that we have sent away Israel from serving us?'" (Shemos 14:5)
The Ramban asks a fascinating question: Why were Pharaoh and the Egyptians surprised that Bnei Yisrael had fled and were not coming back? After all, the Egyptians had explicitly given permission to Bnei Yisrael to leave! However, that is not what the Egyptians believed as the verse above states, “It was told to the king of Egypt that the people had fled...” The Hebrew word for “fled” is “חַרָב” which is a term that implies that the Egyptians believed that Bnei Yisrael had left without permission.
The Ramban explains that the Egyptians had convinced themselves that Bnei Yisrael would return after a three-day trip in the wilderness, despite never having secured such a promise from them. While Moshe Rabbeinu had initially requested a three-day journey to serve Hashem, the final negotiation with Pharaoh resulted in an unconditional release. However, the Egyptians chose to hear what they wanted to hear, so they heard the initial request of Moshe and chose to ignore the final negotiation with Pharaoh. Now that they believed that they were wronged and that Bnei Yisrael should have returned to Egypt, they felt fully justified in their subsequent pursuit to bring them back.
This teaches us an important lesson about truth and self-deception. Often, when we want something badly enough, we hear what we want to hear rather than hearing what was actually said or agreed upon. This can lead to courses of action that we erroneously feel are justifiable - courses of action that we would not have taken and are not justifiable which we would have realized if we would have listened more carefully.
