Ps 83:3

“"Even the sparrow finds a home, and the turtledove a nest in which she puts her young." For the present, let us be satisfied with a simple interpretation. Notice all that the verse implies: I long, O Lord, for your eternal dwelling places; my soul yearns and pines for the courts of the Lord; I long for some place to dwell, a nest for my soul and my body. The birds that fly about to and fro with no restraint, nevertheless, after their flight, have a place and a nest in which to rest. How much more ought not my body and soul procure for itself a resting place?”

“You have heard a groan in the winepress, "My soul longs and fails for the courts of the Lord:" hear how it holds out, rejoicing in hope: "My heart and my flesh have rejoiced in the living God." Here they have rejoiced for that cause. Whence comes rejoicing, but of hope? Wherefore have they rejoiced? "In the living God." What has rejoiced in you? "My heart and my flesh." Why have they rejoiced? "For," says he, "the sparrow has found her a house, and the turtle-dove a nest, where she may lay her young" [Psalm 84:3]. What is this? He had named two things, and he adds two figures of birds which answer to them: he had said that his heart rejoiced and his flesh, and to these two he made the sparrow and turtle-dove to correspond: the heart as the sparrow, the flesh as the dove. The sparrow has found herself a home: my heart has found itself a home. She tries her wings in the virtues of this life, in faith, and hope, and charity, by which she may fly unto her home: and when she shall have come there, she shall remain; and now the complaining voice of the sparrow, which is here, shall no longer be there. For it is the very complaining sparrow of whom in another Psalm he says, "Like a sparrow alone on the housetop." From the housetop he flies home. Now let him be on the housetop, treading on his carnal house: he shall have a heavenly house, a perpetual home: that sparrow shall make an end of his complaints. But to the dove he has given young, that is, to the flesh: "the dove has found a nest, where she may lay her young." The sparrow a home, the dove a nest, and a nest too where she may lay her young. A home is chosen as for ever, a nest is framed for a time: with the heart we think upon God, as if the sparrow flew to her home: with the flesh we do good works. For you see how many good works are done by the flesh of the saints; for by this we work the things we are commanded to work, by which we are helped in this life. "Break your bread to the hungry, and bring the poor and roofless into your house; and if you see one naked, clothe him:" [Isaiah 58:7] and other such things which are commanded us we work only through the flesh....We speak, brethren, what ye know: how many seem to do good works without the Church? how many even Pagans feed the hungry, clothe the naked, receive the stranger, visit the sick, comfort the prisoner? How many do this? The dove seems, as it were, to bring forth young: but finds not herself a nest. How many works may heretics do not in the Church; they place not their young in a nest. They shall be trampled on and crushed: they shall not be kept, shall not be guarded....In that faith lay your young: in that nest work your works. For what the nests are, what that nest is, follows at once. Having said, And the dove has found herself a nest, where she may lay her young; as if you had asked, What nest? "Your altars, O Lord of Hosts, my King and my God." What is, "My King and my God?" You who rules me, who has created me.”

“In heart, let us migrate from living in this world, from which we are rapidly going to migrate in the body, that that heavenly dwelling may receive us, concerning which the apostle says that we have an eternal dwelling from God, a house not made by hands, in the heavens. Concerning this dwelling it has been written: "Happy are those who live in your house, ever singing your praise." There, just as there is an eternal dwelling, so there is eternal praise. Those who live there always praise God because they are always exulting about God and in God; and just as for those who give praise, there is the sweet eternity of a holy dwelling, so the eternal sweetness of giving praise remains for those who dwell there.”