Which Resha'im are these?
Rashi: They are Do'eg and the slanderers of the generation who put hatred between me and Sha'ul.
Rashi (7, from Sanhedrin 26a): They are Shevna and his cohorts (Radak citing Shocher Tov - Yo'ach. They wrote a letter, inserted it in an arrow and shot it out the window. [Sancheriv's camp] opened it for Sancheriv; it said, all of Yisrael want to make Shalom with you, but Yeshayah and Chizkiyah do not let them.)
Radak: They are those who reveal about David (where he wants to escape).
Malbim: They sit in ambush in the dark to shoot arrows covertly, to kill the straight.
What is the meaning of "Yidrochun"?
Rashi: This expression is used for drawing a bow, for when it is strong, one must step on it when he wants to draw it.
What bow is discussed?
Rashi: Their tongue; they draw their bow of Sheker.
Radak: It is the way of Resha'im to shoot arrows covertly at the straight. This is a metaphor for informing; also other [Resha'im] to whom I flee will reveal about me.
What is "Yeser"?
Rashi: It is the string [of the bow].
Why does it say "Liros" (infinitive)?
Radak: They want to shoot, but they do not. Their deeds and intents do not help, for I trusted in Hashem.
Malbim: They prepare the arrows on the bow-string in order to shoot at the straight, and they succeed!
What is the meaning of "b'Mo Ofel"?
Rashi: It is hidden.
Who are "Yishrei Lev"?
Rashi: David and the Kohanim of Nov.
Rashi (7, from Sanhedrin 26a): They are Yeshayah and Chizkiyah (refer to 11:2:1:2).
Radak: It is me (David); today I have no sin.