What is the meaning of "Tehosesu"?
Rashi citing Menachem: This is like "Hesayu Le'achlah" (Yirmeyah 12:9), "va'Yesei Roshei Am" (Devarim 33:21) - how long will you gather against a man?!
Rashi #1: It is an expression of Havos, intents for breakage and guile. The Hei and Sov are the root. The singular form is Haves, just like Maves is from the root Mes.
Rashi #2: You elongate your tongues against people for evil.
Malbim: Even though you intend [to kill due to someone else, you are liable]; refer to 62:4:2:2.
What is the meaning of "Al Ish"?
Radak: [The enemies have intents for breakage and guile] for every Yisrael.
Malbim: You bring breakage on David due to a man (Sha'ul). Even though you do so due to Sha'ul, also you are considered murderers. You are like a leaning wall over a flimsy fence. The wall falls on the fence and makes it fall on a man underneath. Do not say that the primary killer was the wall. Also the fence caused his death - if it were strong, it would not have fallen due to the wall! The murder is attributed to both of them. Similarly, Sha'ul pushes them to fall on David and kill him. The murder is attributed also to them. If they were strong-minded, they would not heed Sha'ul to kill without reason.
Why did he say "Teratzechu Chulchem"?
Radak: May all of you be murdered.
Malbim: You are considered murderers; refer to 62:4:2:2.
What is the comparison to a leaning wall [and a weak fence]?
Rashi: It is ready to fall on people.
Radak: The enemies should be like a wall about to fall. All their days, they should fear, and in the end they will be murdered.
Malbim: Refer to 62:4:2:2.
