What is the meaning of "Aha"?
Rashi: It is an expression of worry - what will happen to me?!
What is the meaning of "Ki Al Ken Ra'isi"?
Rashi: Because I saw an angel of Hashem, therefore I am worried.
Malbim: "Lo Yir'ani ha'Adam va'Chai" (Shemos 33:20). As long as a person is in a body, he cannot see the Shechinah, only right before death - "Ki Li Tichra Kol Berech" (Yeshayah 45:23). Therefore, he thought that he will die.
Malbim: According to the Meforshim that he was unsure whether he saw an angel or a Navi, he thought that one cannot see an angel, for it is purely spiritual. How can a physical person see it, if not right before death? Then, he is like an angel, for the spiritual Nefesh is ready to remove the Golem (physical body), just like an angel that appears in a Golem is prepared to remove it immediately. Gid'on and Mano'ach saw the angel when it disappeared, i.e. the moment it removes its Golem. A living person cannot see it then. 1 About this, Eliyahu said "if you see that I am taken from you 2 " (Melachim 2 2:10).
Malbim: Gid'on became afraid when he saw him as an angel, like he is. Beforehand, he saw him in a human form. (This explains why Hagar did not fear after seeing four angels (refer to be 16:13:3:1); she saw them in physical form. - PF)
Then you will know that you will receive twice my Ru'ach. I.e. if not, you would not be able to see this (Malbim 13:20).
