(Ezekiel, xlviii.35)

As birds their infant brood protect,
And spread their wings to shelter them,
Thus saith the Lord to His elect,
"So will I guard Jerusalem."

And what then is Jerusalem,
This darling object of His cares?
Where is its worth in God's esteem?
Who built it? who inhabits there?

Jehovah founded it in blood,
The blood of His incarnate Son;
There dwell the saints, once foes to God
The sinners whom He calls His own.

There, though besieged on every side,
Yet much beloved and guarded well,
From age to age they have defied
The utmost force of earth and hell.

Let earth repent, and hell despair,
This city has a sure defence;
Her name is call'd, "The Lord is there,"
And who has power to drive him hence?

William Cowper

http://www.poemhunter.com/poem/jehovah-shammah/