Why does it say "Gam Ani..."?
Rashi (3): Just like they desired these evil ways, I will choose mockery of them!
Radak: Just like they destroy their ways, I will choose to destroy their deeds. This is like "vecha'Aliloseichem ha'Nishchasos" (Yechezkel 20:44). It is an expression of wrecking and destruction.
Malbim: Just like they chose for themselves Mitzvos that I did not choose, as if they come to jest - so I will choose to jest over them.
What are "Ta'aluleihem"?
Rashi: It is to be Olel (jest) in them, like "His'alalt Bi" (Bamidbar 22:29).
What are "Megurosam"?
Rashi: They are what they fear [Radak - i.e. the sword and hunger]. Malbim - this is Midah k'Neged Midah for "uv'Shikutzeihem Nafsham Chafetzah" (3).
How did Hashem call to them?
Rashi: He said "Shim'u Shamo'a [Elai]" (55:2) and "Shuvu Elai [v'Ashuvah Aleichem]" (Mal'achi 3:7).
Radak: He sent the Nevi'im to return them to the good path.
What should they have answered?
Rashi: 'I heard.'
Radak: They should have accepted His words.
Why does it say both "va'Ya'asu ha'Ra b'Einai" and "uva'Asher Lo Chafatzti Bacharu"?
Malbim: "Va'Ya'asu ha'Ra b'Einai" is transgressing Lavim; "uva'Asher Lo Chafatzti Bacharu" are Mitzvos Aseh that they concocted for themselves.