John Gill Bible Commentary

Prepare ye war against her,.... Not only proclaim it, but prepare themselves for it; get everything ready for the siege, and begin it. These are either the words of the Lord, calling upon the Chaldeans in his providence to act such a part against Jerusalem; or of the Chaldeans themselves, stirring up one another to it; which latter seems to be the sense; since it follows: arise, and let us go up at noon; scale the walls, and take the city; which, though in the heat of the day, and not so proper a time, yet such was the eagerness of the army, and their confidence of carrying the place at once; and concluding there was no need of waiting till the evening, or of taking any secret measures for the siege; they propose to go up at noon, in the heat of the day, and in the sight of their enemies, and storm the city: woe unto us, for the day goes away, for the shadows of the evening are stretched out; which some take to be the words of the besiegers, lamenting they had lost time, had not proceeded according to their first purpose, had neglected going up at noontime, and now the evening was coming upon them; or as being angry, and out of humour, that the city was not taken by them so soon as they expected: though, according to Kimchi, they are the words of the prophet; and he may represent the besieged, mourning over their unhappy case and circumstances; the day of prosperity declining, and nothing but darkness and distress coming upon them.