וְעַתָּ֗ה כְּבֹ֨א הַסֵּ֤פֶר הַזֶּה֙ אֲלֵיכֶ֔ם וְאִתְּכֶ֖ם בְּנֵ֣י אֲדֹנֵיכֶ֑ם וְאִתְּכֶם֙ הָרֶ֣כֶב וְהַסּוּסִ֔ים וְעִ֥יר מִבְצָ֖ר וְהַנָּֽשֶׁק׃
’And now as soon as this letter cometh to you, seeing your master’s sons are with you, and there are with you chariots and horses, fortified cities also, and armour;
Rashi
opposite the ascent to the armory opposite the place where the mighty men would ascend to the weapons. According to the simple interpretation of the verse, it appears that there was a place near the wall where the mighty men kept their weapons, as it is stated: (II Kings 10:2) “...and cities (sic) of fortification and arms.”
Rashbam
ישק, he will motivate people through clever use of weaponry to attack their enemies. The use of the word נשק meaning weapons occurs in Kings II 10,2 as עיר מבצר והנשק, “a fortified city and weaponry.” We also find it used in this sense in Psalms 78,9 נושקי רומי קשת, “being armed and carrying bows.”