Yea, the sparrow hath found an house, and the swallow a nest for herself, where she may lay her young. Both sparrows and swallows abound in Palestine. Canon Tristram found the nest of a sparrow "so closely allied to our own that it is difficult to distinguish it," in a chink of the Haram wall at Jerusalem, near the Golden Gate.
An anecdote related by Herodotus shows that sparrows built about the Greek temples. The general meaning of the figure in this place seems to be, "If even birds love to build their nests, as they do, in the sacred precincts, how much more reason has the believing heart to find its home in the house of its God!"
But the psalmist thinks it enough to suggest the parallel, and does not stop to carry it out. Even thine altars. The "altar" is put, by metonymy, for the temple itself. O Lord of hosts, my King, and my God (comp.