Charles H. Spurgeon on Psalms 84:3

Yea, the sparrow hath found an house. He envied the sparrows which lived around the house of God, and picked up the stray crumbs in the courts thereof; he only wished that he, too, could frequent the solemn assemblies and bear away a little of the heavenly food. And the swallow a nest for herself, where she may lay her young. He envied also the swallows whose nests were built under the eaves of the priest's houses, who there found a place for their young, as well as for themselves. We rejoice not only in our personal religious opportunities, but in the great blessing of taking our children with us to the sanctuary. The church of God is a house for us and a nest for our little ones. Even thine altars, O Lord of hosts. To the very altars these free birds drew near, none could restrain them nor would have wished to do so, and David wished to come and go as freely as they did. Mark how he repeats the blessed name of Jehovah of Hosts; he found in it a sweetness which helped him to bear his inward hunger. Probably David himself was with the host, and, therefore, he dwelt with emphasis upon the title which taught him that the Lord was in the tented field as well as within the holy curtains. My King and my God. Here he utters his loyalty from afar. If he may not tread the courts, yet he loves the King. If an exile, he is not a rebel. When we cannot occupy a seat in God's house, he shall have a seat in our memories and a throne in our hearts. The double "my" is very precious; he lays hold upon his God with both his hands, as one resolved not to let him go till the favour requested be at length accorded.