What is the meaning of "va'Yikarei Avshalom Lifnei Avdei David"?
Rashi, Targum Yonasan: This is an expression of Mikreh (they happened to encounter him).
What is "Shovech ha'Elah"?
Radak: It is a branch of a tree. A thicket of branches is called Shovech.
How did his head get caught in the branch?
Radak: He had abundant hair 1 . Because he was haughty about his hair, he was hung [and died] from his hair (Sotah 9b).
Tosfos (Nazir 4a): Even though he shaved shortly before this, he did not totally shave his hair, for he was hung by his hair!
Did Avshalom not have a sword to cut his hair, to free himself?
Rashi citing Sotah 10b: He was about to cut it, and then saw Gehinom underneath him.