Why is "Anochi" repeated?
Malbim: You say "Uri Zero'a Hashem" (9), as if I changed from days of yore. You err; I am like I was. I did not change; I still console you.
Why does it say "Mi At"?
Rashi: A daughter of Tzadikim like you, full of merits, why do you fear a man, who is destined to fie?!
Malbim: I did not change - you changed! I do not recognize you at all. You are not the nation that I redeemed from Egypt. They did not fear people; they trusted in My salvation. You fear mortals!
Why does it say "Menachem" (plural), "Mi At" (feminine singular), and "va'Tishkach
Radak: The plural refers to the individuals. Masculine singular is used for the Klal, and feminine singular for the Keneses (gathering).
Why does it say "[va'Tir'i] me'Enosh Yamus"?
Radak: He is mortal; if he pains you today, he will not pain you tomorrow (he will die).
R. Yonah (Mishlei 3:26): Fearing a person is sin and lowliness of the Nefesh.
Is man Chatzir?
Radak: He is like Chatzir (grass; it dries quickly; the prefix Kaf is omitted. The same applies to "Gur Aryeh Yehudah" (Bereishis 49:9).