The twelfth chapter of the book of Zechariah is timid about neither the Zion-centered nationalism that it celebrates nor the corresponding defanging of the nations that besiege Jerusalem ‘in that day’. To the contrary, the Lord announces through his prophet that he will make Jerusalem ‘a cup that sends all the surrounding peoples reeling’. Then, via the extravagant mixing of metaphors that is characteristic of the genre, the Lord ‘will make Jerusalem an immovable rock for all the nations. All who try to move it will injure themselves.’
The harassed Judahite city will become the Archimedean point that cannot be shifted while its attackers are levered violently this way and that, their former belligerence reduced suddenly to drunken impotence.
One might expect, especially that reader who blinkers himself by peering exclusively through the lens of modern and post-modern sentimentalities, that Zion’s residents here are merely the righteous victors and her attackers simply the villainous victims of Jerusalem’s vindication from above.
As so often, this slice of prophetic literature has more subtle things to say, its knife cutting with both edges.
On that day the LORD will shield those who live in Jerusalem, so that the feeblest among them will be like David, and the house of David will be like God, like the Angel of the LORD going before them. On that day I will set out to destroy all the nations that attack Jerusalem.
So far, the categories of table-turning vindication are somewhat familiar to us. It is true that the text daringly elevates Davidic leadership beyond normal bounds. Yet the bifurcation of the human protagonists into good and bad is conventional, hardly preparing us for what follows.
And I will pour out on the house of David and the inhabitants of Jerusalem a spirit of grace and supplication. They will look on me, the one they have pierced, and they will mourn for him as one mourns for an only child, and grieve bitterly for him as one grieves for a firstborn son. On that day the weeping in Jerusalem will be great, like the weeping of Hadad Rimmon in the plain of Megiddo. The land will mourn, each clan by itself, with their wives by themselves: the clan of the house of David and their wives, the clan of the house of Nathan and their wives, the clan of the house of Levi and their wives, the clan of Shimei and their wives, and all the rest of the clans and their wives. (Zechariah 12:8–14 NIV)
Then, as though to weave the whole picture forcibly together so that no one might blanch at this bit of intense mourning-in-victory, the text storms forward:
‘On that day I will strike every horse with panic and its rider with madness,’ declares the LORD. ‘I will keep a watchful eye over the house of Judah, but I will blind all the horses of the nations. Then the leaders of Judah will say in their hearts, “The people of Jerusalem are strong, because the LORD Almighty is their God.”‘ (Zechariah 12:4–5 NIV)
It is not difficult to see how the text has flourished in the hands of Christian interpreters, with its unlikely reference to looking upon the Lord, ‘the one whom they have pierced.’
Laying aside that detail for a moment, one finds in this text that curious energy with which the biblical prophets practice their surgery upon the hearts of those who have benefitted from YHWH’s undeserved rescue.
How are we to understand the presence of bitter grief and mourning even as the sights and sounds of YHWH’s vindicating rescue are—in the lavish picture painted by the text—all around?
If one is to take these ‘minor prophets’ seriously, the ‘day of the Lord’ is both light and deep darkness. YHWH’s rescue as it is splayed onto the prophetic canvas in vivid color, is real, worthy, and life-restoring. Yet those who receive it know that it should not have been this way. Joyous relief resolves into penitent grief and then back again. Neither obviates the other.
Each contributes to the dynamic with which the chapter ends:
They will call on my name and I will answer them; I will say, ‘They are my people,’ and they will say, ‘The LORD is our God.’
Canter Bridge 
To call attention to both aspects of the DOTL–great insight. I’d been thinking about the joy of rescue, but hadn’t gone to the point of considering the ‘lamentable’ need for it. Might this be part of what lies behind the ‘tears in heaven’ John describes?
Dan’l, I really like that! Thanks for posting the connection you glimpse there.