Rashi: They rejoiced when Nebuchadnetzar's lottery fell on Yerushalayim, and they reviled Me and My nation, saying that their idolatry is exalted, to kill many.

Rashi (36): They revile Yisrael because Nebuchadnetzar destroyed them.

Radak, Malbim: They reviled Yisrael and rejoiced over their exile and leaving their land. Initially, Melech Bavel conquered [Bnei Amon], and they were slaves to him. Afterwards they rebelled, like Tzidkiyah rebelled. Nebuchadnetzar's intent was [to destroy] Bnei Amon and Yerushalayim. His lottery fell on Yerushalayim, and he destroyed it. He returned to his land, and did not go to Bnei Amon. Therefore, Bnei Amon reviled Yisrael in their Galus and shame. Also Nevu'as Tzefanyah says (2:8) "Shamati Cherpas Mo'av v'Gidufei Bnei Amon."

Rashi (36): This refers to Nebuchadnetzar's double sword, to go in two ways ? to Yerushalayim and Bnei Amon, like in the previous Parashah.

Radak: The sword that was sharpened for Yisrael, it is Pesuchah (refer to 21:33:3:1-2) also for them. If it will not be now via Nebuchadnetzar, it will be via Paras and Madai.

Malbim: Also, Balis Melech Bnei Amon sent Yishmael ben Nesanyah to kill Gedalyah ben Achikam, so there will be no remnant [of Bnei Yisrael] in Eretz Yisrael. This itself caused that later Nebuchadnetzar came to take vengeance and destroy Bnei Amon! Do not think that Nebuchadnetzar's sword will not come upon you. It already left its case; it is open, and will not return to its case! Even though now it is Merutah (dulled), i.e. he will not come against you now, it is prepared to slaughter later. When he conquers Yerushalayim, his sword will return against you.

Radak #1, Targum Yonasan: It is open, i.e. out of it scabbard. When it is in its case, it is closed.

Radak #2: Some say that it is polished ¹ . The same applies to "Cherev Paschu Resha'im" (Tehilim 37:14).

Radak: [The sword was sharpened and cleaned] to endure [much killing]. This is like "v'Nora Me'od u'Mi Yachilenu" (Yo'el 2:11; Radak there ? who can bear it?)

Radak citing his father: It is like Leha'achil (to feed). Also "Azin Ad Tevunoseichem' (Iyov 32:11) is like A'azin (I will listen); "v'Lo Yahel Sham Aravi" (Yeshayah 13:20) is like Ye'ehal. The man who holds the sword, he feeds; the sword consumes, and the victims are consumed. It was sharpened in order to feed.

Radak citing Targum Yonasan: To destroy.

Malbim: This is one of the reasons why it was Merutah ? (it was dulled) so he can hold it in his hand [and kill]. I.e. since he departed now from Bnei Amon, he will have strength to holds the sword after he defeats Yerushalayim. Had he fought Amon and Yisrael together, he would not have had strength to fight two nations. Also refer to 21:33:5:3.

Rashi: In order that its shining appearance not be darkened via the bodies [that it will kill].

Radak: [The sword was sharpened and cleaned] to shine, to scare nations.

Malbim: This is the other reason why it was Merutah ? so it will shine and scare those who see it ? "Lema'an Heye Lah Barak Moratah" (15). Since fear of him fell on all neighbors of Eretz Yisrael, he conquered them easily.