The question is about Psalm 84:3:
Even the sparrow finds a home, and the swallow a nest for herself, where she may lay her young, at your altars, O Lord of hosts, my King and my God.
First, “at” is not “in”, and even if the verse said “in”, this does not mean “located inside in a physical sense”. I don’t get any sense of physical desecration, but something rather different. I’m no expert in Hebrew, but I note that while the various versions from KJV through NET vary in the sense they draw out of the verse, the consistent theme that emerges is of finding comfort and security. And this matches the sense of the context — of the psalmist who cries out for the peace and safety to found in God’s house, and by extension, God’s hands.
And if God cares enough for the sparrow to offer it a home, how much more for us?
“Therefore I tell you, do not worry about your life, what you will eat or drink; or about your body, what you will wear. Is not life more important than food, and the body more important than clothes? Look at the birds of the air; they do not sow or reap or store away in barns, and yet your heavenly Father feeds them. Are you not much more valuable than they? (Matthew 6:25-26)
If this Psalm is placed in the context of Ezra 3:1-6 and was composed by one of the exiles just returned from Babylon, we can see the relevance of the remark “How lovely are thy tabernacles”(booths made for this particular feast of the Lord), we can sense the longing for the courts of the Lord (not yet rebuilt) compared with the “tents of wickedness” they had left behind in Babylon. The “Valley of Baca” would refer to the same experience as Psalm 137:1 and the sparrow and swallow nests would be in evidence in the ruins of the former temple, after 70 years of desolation and neglect. The following Psalm 85 fits the same context perfectly.