(4) Prepare ye war.--Literally, Sanctify. The opening of the battle was accompanied by sacrifices, divinations, and prayers. Compare Deuteronomy 20:1-3 for the practice of the Israelites, and Ezekiel 21:20-22 for that of the Chaldaeans, which was, of course, present to Jeremiah's mind. The cry thus given with dramatic force comes from the soldiers of the invading army impatient for the fight. They are so eager that, instead of resting at noon, as usual, for their mid-day meal, they would fain press on for the assault. Their orders are against this, and, as the shadows lengthen, they raise their cry of complaint, "Alas for us, the day declines . . ." Then, impatient still, unwilling to wait, as their commanders bid them, for an attack at day-break, they shout, "Let us go by night."

Verse 4. - Prepare ye war; literally, sanctify (or, consecrate) war. The foes are dramatically described as urging each other on at the different stages of the campaign. The war is to be opened with sacrifices (comp. Isaiah 13:3 with 1 Samuel 13:9); next there is a forced march, so as to take the city by storm, when the vigilance of its defenders is relaxed in the fierce noontide heat (comp. Jeremiah 15:8); evening surprises the foe still on the way, but they press steadily on, to do their work of destruction by night. The rapidity of the marches of the Chaldeans impressed another prophet of the reign of Josiah - Habakkuk (see Habakkuk 1:6, 8). Woe unto us! for the day goeth away; rather, Alas for us! for the day hath turned.

6:1-8 Whatever methods are used, it is vain to contend with God's judgments. The more we indulge in the pleasures of this life, the more we unfit ourselves for the troubles of this life. The Chaldean army shall break in upon the land of Judah, and in a little time devour all. The day is coming, when those careless and secure in sinful ways will be visited. It is folly to trifle when we have eternal salvation to work out, and the enemies of that salvation to fight against. But they were thus eager, not that they might fulfil God's counsels, but that they might fill their own treasures; yet God thereby served his own purposes. The corrupt heart of man, in its natural state, casts out evil thoughts, just as a fountain casts out her waters. It is always flowing, yet always full. The God of mercy is loth to depart even from a provoking people, and is earnest with them, that by repentance and reformation, they may prevent things from coming to extremity.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.