What is "mi'Toch ume'Chamas"?
Rashi: It is from blows and theft. Toch is like Chak 1 Tuchos (Gitin 20a, i.e. carving out the inside of the letters). This is like "v'Ish Techavim" (Mishlei 29:13).
Radak: Toch is swindling without [the victim's] knowledge. Chamas is robbery with knowledge.
Malbim: This corresponds to crushing the oppressor (verse 4). There is open Chamas (robbery), and Chamas hidden via deception and overcharging; this is called Toch.
It seems that it should say so. Our text of Rashi says 'Toch Tuchos'. I did not find this expression anywhere else! (PF)
Why does it say "Yig'al"?
Malbim: Ge'ulah is due to kinship (refer to 69:19:1:2). He considers the poor like his relatives; he is their Go'el.
Why does it say "v'Yeikar Damav b'Einav"?
Radak: Blood of Aniyim is dear in his eyes, therefore he saves their lives and redeems them from the Resha'im, lest they spill their blood. This is like "Yakar b'Einei Hashem ha'Mavsah la'Chasidav" (116:15).
Malbim: If one kills an Oni, money will not help him. [The king] will do an absolute Din to kill the murderer. Via this he will merit great honor, that kings will bow to him.
