Why does it say "Al he'Harim"?
Rashi: Due to Churban of the mountains. Radak - this is the primary place where flocks graze.
Radak: [Yirmeyah] went to the mountains to make his voice heard from afar.
Malbim: [Hashem says] I will not cry over them. Just the contrary, I will take vengeance and do to them like is proper for their deeds! I will cry over the mountains, which did not sin, and now, no one will pass there.
What are "Ne'os Midbar"?
Rashi: They are habitations of shepherds in the Midbar. Ne'os is an expression of Naveh, like "Ne'os Elokim", "l'Veischa Na'avah Kodesh" (Tehilim 83:13, 93:5).
Radak: These are tents and dwellings in the Midbar, like "v'Nadamu Ne'os ha'Shalom" (25:37). It is the same when there is a Vov (in place of the Aleph), e.g. "Naveh Meshulach v'Ne'ezav" (Yeshayah 27:10), "Nevos Keros Ro'im" (Tzefanyah 2:6). Some Midbaros have pasture - "va'Yinhag Es ha'Tzon Achar ha'Midbar" (Shemos 3:1); Targum Onkelos is 'l'Vasar Shefar Ra'aya l'Midbara.' It says also "Al Pnei Derech Es ha'Midbar 1 " (Shmuel II, 15:23). When the Navi saw Churban ha'Aretz, he said that he will cry and lament in places of pasture, for they were made desolate from passersby. There is no need to say that shepherd's tents are not set there - no one even passes to graze flocks, and the sound of flocks is not heard, for all went into captivity.
Radak (Shmuel II, 15:23): A place for animals to graze is called Midbar, whether it is close to the city or far. Therefore it says "v'Ra'u Kevasim k'Davram" (Yehoshua 5:17), "k'Eder b'Soch ha'Davro" (Michah 2:12). The Targum of "va'Yinhag" (Bereishis 31:18) is u'Devar.
What is the meaning of "Nitzesu"?
Rashi: It is an expression of Tziyah (dry). The same applies to "Nitzesah" (verse 11).
Why does it say "me'Of ha'Shamayim"?
Radak #1: This is an exaggeration.
Radak #2: This is due to Churban ha'Aretz. Birds do not dwell in a Midbar, rather, in places where they find seeds, Peros and budding trees.
Why does it say "Nadedu Halachu"?
Rashi: In the end they will go. For 52 years no man passed in Yehudah (Shabbos 145b), from the exile of Tzidkiyah until Koresh Melech Paras authorized [Jews to return]; the Gematriya of "Behemah" (52) hints to this. The calculation is clear from Megilah 11b.
