Why does it say "Tzon Ovdos"?
Radak: No one seeks them. So were My nation until the time that Bavel will be destroyed. Then, someone will seek them!
Malbim: Hashem says, My nation was like Hefker.
Why is it written Hayah, and we pronounce it Hayu?
Radak: The Kesiv refers to the Klal (it is singular), and the pronunciation refers to the individuals (plural).
What is the meaning of "Ro'eihem His'um"?
Rashi: Their leaders made them stray from Me.
Radak: Their kings caused them to perish; they tricked them into going in an evil path.
What is the meaning of "Harim Shovevum"?
Rashi: [Their kings made them stray] to idolatry on the mountains.
Radak #1: It is an expression of expulsion and sending. The same applies to "Ki Shevavim Yihyeh" (Hoshe'a 8:6). [The grammarian] R. Yonah explains that they sent them to the mountains.
Radak #2: They broke and crushed them when they went to exile, from mountain to mountain and from mountain to hill. Also "Ki Shevavim Yihyeh" is an expression of breaking and crushing. The same applies to "v'Shovavticha v'Shisheisicha" (Yechezkel 39:2).
Malbim: First they served idolatry in their land.
Why does it say "me'Har El Giv'ah"?
Radak: Refer to 50:6:4:3.
Malbim: Later they served idolatry in their enemies' land.
What is "Rivtzam"?
Metzudas Tziyon: It is where they lied and rested.