Whose sword is the Pasuk referring to?
Rashi: The expression 'Hava'as Cherev' always pertains to that of an invading army.
What are the implications of "N'kam Bris"?
Rashi#1: It implies that there is a vengeance that is not based on the covenant, such as the blinding of the eyes of Tzidkiyahu.
Rashi #2: It means that Hashem will avenge the Bris that He made with you and which you abrogated. 1
Rashbam: See above, Pasuk 15.
Presumably, the Seforno interprets "Sefer ha'Beris" as Mishpatim, which contains the Mitzvos that Hashem gave Yisrael at Har Sinai, where He entered into the Bris with them.
Seforno: As occurred in the days of Malchei Yisrael, as foretold by the Navi Elisha in Melachim 2, 8:12.
Seforno: See Kesuvos, 30a.
What is thee meaning of "Vene'esaftem"?
Rashi: It means that they will be gathered from the fields outside into the towns, on account of the siege.
What is the connection between the pestilence and being handed over to the enemy?
Rashi: When they go out to bury the people who died in the plague of pestilence, 1 the enemy will capture them.
Seforno: Being handed over to the enemy refers to the ten tribes falling into the hands of Sancheriv, King of Ashur.
Rashi: Since it is forbidden to leave an unburied corpse in Yerushalayim overnight.
QUESTIONS ON RASHI
Rashi writes that the blinding of the eyes of Tzidkiyahu is not based on the Bris. What does this mean?
Moshav Zekenim: It is not written in the Torah. Even though it says "Yakechah Hashem... uv'Ivaron" (Devarim 28:28), that refers to blindness from Shamayim.