Isaiah 13

what I remember:
To the Lord's enemies, the Day of the Lord is a terrible threat. Here, Babylon is warned about what is waiting for them on the Day of the Lord -- utter destruction. There will be pain like childbirth, no pity for the women or the children - everything will be plundered, and everyone will flee. Enemies will a abound, and Babylon will be conquered never to be settled again. It'll be wilderness.

Verse 6 seems to sum up the chapter.

Wail, for the day of the LORD is at hand! it will come as destruction from the Almighty.

references to the "Day of the Lord" in this chapter:
v. 6 "Wail, for the day of the LORD is at hand! It will come as destruction from the Almighty."
v. 9 "Behold, the day of the LORD comes, Cruel with both wrath and fierce anger, to lay the land desolate; and He will destroy its sinners from it."
v. 13 "Therefore I will shake the heavens, And the earth will move out of her place, In the wrath of the LORD of hosts and in the day of His fierce anger."

I wonder if the prophecies in this chapter are the ones that were fulfilled when Babylon was conquered (was it by William the Conqueror?) never to be rebuilt, or if these are referring to future times yet. Both seem possible. b. 10 talks of the stars and sun and moon not giving light -- which seems similar to the prediction in Revelation, but much of the rest of the chapter seems specific to Babylon - it won't be rebuilt, for example.

In any case, it seems a pretty terrible thing to be on the side that isn't the LORD's side on this Day of the Lord. It kind of changes the meaning of "The Day of the Lord" for me -- I had always thought of it as a terrific, victorious, happy day. Now I see that for the enemies side, it's a terrible ruin.