1)
Why does it say "va'Yarchivu Alai Pihem"?
1.
Radak: They excessively jest and talk about me when they see me exiled from place to place.
2.
Malbim: Refer to 35:20:1:2.
2)
What is "He'ach He'ach"?
1.
Rashi: It is an expression of Simchah. He boasts upon seeing his desire fulfilled. Radak - it is doubled to show excessive Simchah. We similarly find "Amrah Tzor Al Yerushalayim He'ach" (Yechezkel 26:2).
3)
Why did they say "Ra'asah Eineinu"?
1.
Radak: Our eye saw what we imagined and wanted. This is like "uv'Oyvai Ra'asah Eini" (54:9).