What is "Evkeh bi'Vchi Yazer"?
Rashi citing Targum Yonasan: Just like I brought camps against Yazer, I will bring murderers against Sivmah.
Rashi (here and Yirmeyah 48:32): When this Nevu'ah was said, Yazer was already destroyed. It is close to Mo'av. The Navi says, I will lament for you (ha'Gefen Sivmah), similar to the lamentation for Yazer, for you will be destroyed like it. Radak - "bi'Vchi" applies also to Gefen Sivmah.
Radak: The Navi speaks on behalf of Mo'av.
Radak (Yirmeyah 48:32): Other cities of Mo'av, when they hear the crying of Yazer, will [immediately] cry for you, ha'Gefen Sivmah, for they know that it will be [destroyed] like Yazer.
Malbim: When I cry for Yazer, I will cry also for Gefen Sivmah. When Yazer was destroyed, it was the end also of the Giborim of Sivmah.
Why does it say "Gefen Sivmah"?
Rashi: It was a land of vineyards.
Radak (Yirmeyah 48:32): A vine is a parable for the nation. The enemy will kill some of them, and take some of them to exile 1 .
I.e. some of the branches spread out too much. The owner uproots some of them, and harvests (removes the grapes) from some. (PF)
What is the meaning of "Arayavech"?
Rashi: Esraveh (I will be saturated) with tears over you (Radak - Cheshbon and El'alei). The word is in place of two words (Esraveh Alayich), like "Banai Yatz'uni" (Yirmeyah 10:2; Yatz'u Mimeni). Radak - this is an exaggeration, as if Hashem's tears are rain that saturates the land.
Malbim: With these tears Araveh (I will saturate) also Cheshbon and El'alei. You are compared also to them.
Why does it say "Netishosayich"?
Rashi: Because it compared it to a vine, it compared its Giborim to branches that spread out. Radak - they are a metaphor for Goyim.
What are "Keitzech"?
Rashi: They are figs, which dry in the Kayitz (summer).
Radak: Kayitz are summer fruits, moist or dry. At the time of the harvest, the enemy plundered [them].
What is "Heidad"?
Rashi: It is the voice of plunderers. Radak - it is what they shout when they pounce suddenly on a city.
Rashi (Yirmeyah 48:32), Malbim: They used to shout Heidad amidst Simchah, while stomping grapes. Now they will shout it when fleeing the sword. Radak - Yonasan translated, they will not stomp, and will not raise their voices.