Adam Clarke on Psalms 84:3

Yea, the sparrow hath found a house - It is very unlikely that sparrows and swallows, or birds of any kind, should be permitted to build their nests, and hatch their young, in or about altars which were kept in a state of the greatest purity; and where perpetual fires were kept up for the purpose of sacrifice, burning incense, etc. Without altering the text, if the clause be read in a parenthesis, the absurdity will be avoided, and the sense be good. "My heart crieth out for the living God, (even the sparrow hath found a house, and the swallow דרור deror, the ring-dove, a nest for herself, where she may lay; her young), for thine altars. O Lord of hosts!" Or, read the parenthesis last: "My heart crieth out for the living God; for thine altars, O Lord of hosts, my King and my God. Even the sparrow hath found out a house, and the swallow (ring-dove) a nest for herself, where she may lay her young;" but I have no place, either of rest or worship, understood. The Chaldee translates thus: "Even the pigeon hath found a house, and the turtle-dove hath a nest because their young may be offered lawfully upon thine altars, O Lord of hosts, my King and my God." Or, as a comparison seems to be here intended the following may best express the meaning; "Even as the sparrow finds out (seeks) a house, and the swallow her nest in which she may hatch her young; so I, thine altars, O Lord of hosts, my King and my God."