What is "k'Somer Mikshah"?
Rashi: It is beaten with a hammer until it is straight like a date 1 tree.
Radak: Just like a date tree is straight; there is no bend in its body, for its branches are above and [until them] its entire body is straight. So what is beaten with a hammer is straight; the shade stands erect in the form of a person.
Radak: Somer is like Tamar (date); sometimes it has a Cholem, e.g. "v'Hi Yosheves Tachas Tomer" (Shoftim 4:5).
Why does it say that they do not speak?
Radak: There is not even Ru'ach of motion in them, all the more so no Ru'ach of speech!
Malbim: They do not have the form of a Nefesh that speaks, and not even the form of a living Nefesh that moves.
Why does it say "Yinaso"?
Radak: The Aleph and Vov are switched; it should say Yinas'u. Also in "Nasu la'Shav Arecha" (Tehilim 139:20) the Aleph and Vov are switched.
Why does it say not to fear them?
Rashi: Do not fear to separate from (cease serving) them.
Radak: They cannot move by themselves; there is no reason to trust in them or fear them.
To whom do they not do evil?
Rashi: They will not harm you.
To whom do they not benefit?
Rashi: You, [even] if you will serve them.
Radak: They have no power to benefit [anyone].