Or HaChaim on Exodus 15:9/אור החיים על שמות ט״ו:ט׳

1 אמר אויב ארדף אשיג, The enemy had said to himself: "I will pursue, I will overtake, etc." The reason that the Israelites repeated what we knew already about the Egyptians pursuing the Israelites was to extol the manner in which G'd performed the miracle at the sea. G'd had succeeded in lulling the Egyptians into a sense of false security so that they did not consider the pursuit into the sea as hazardous.

2אחלק שלל, "I will divide the spoils." The wicked Pharaoh intended to accomplish three things. 1) Something in which all would share equally, i.e. division of the spoils. 2) He wanted to take the Jews back as slaves as they had been before. He said: "my lust shall be satisfied upon them." He referred to the sense of accomplishment he would feel once he captured the Israelites to make them slaves again. He also hinted that he would treat them at will and oppress them more harshly than previously. 3) He planned to kill Moses and Aaron as well as the elders and leaders of the people. This is what he referred to when he said (in the words of the Israelites) "I will draw my sword and my hand will destroy them." We have an example of the previous Pharaoh attempting to kill Moses by the sword (Exodus 2,15) where Shemot Rabbah 1,31 describes Pharaoh as unsuccessfully attempting to kill Moses by the sword.