Psalm 84.1-4The image is from verse 3, the image of sparrows and swallows making nests in the temple courts.
How lovely is your dwelling place,
Lord Almighty!
My soul yearns, even faints,
for the courts of the Lord;
my heart and my flesh cry out
for the living God.
Even the sparrow has found a home,
and the swallow a nest for herself,
where she may have her young—
a place near your altar,
Lord Almighty, my King and my God.
Blessed are those who dwell in your house;
they are ever praising you.
What I like about the image is how, very plausibly, it places the poet in the temple courts at the time of composition. You can imagine the poet sitting in the temple with the intent to compose a song. The poet begins with expected lines, extolling the temple as home, as the resting place our hearts are yearning for. The poet then pauses and begins to think about what should come next in the song.
And then an unexpected image. Birds nesting in the temple. Where did this image come from?
The origin seems obvious enough. As the poet's eyes take in the temple courts, heart searching for the next lines, the poet looks up at the sky and notices the birds overhead, flying to and fro from their nests high up in the nooks and crannies of the temple. The poet watches the birds meditatively. And then the flash of recognition--Look, even the birds long to live here!
Of course, the poem could have been written at some other time and place, with the birds nesting in the temple as a memory of a past visit. But I've always felt that the insertion of the nesting birds in the poem was most likely a spontaneous insight prompted by the poet actually siting in the temple court while composing the song. The poet's vision caught by the sight of the birds.