Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 15

Sanskrit:

छिद्यमानं यमैरेतै: कृतनीडं वनस्पतिम् ।खग: स्वकेतमुत्सृज्य क्षेमं याति ह्यलम्पट: ॥ १५ ॥

ITRANS:

chidyamānaṁ yamair etaiḥkṛta-nīḍaṁ vanaspatimkhagaḥ sva-ketam utsṛjyakṣemaṁ yāti hy alampaṭaḥ

Translation:

Without attachment, a bird gives up the tree in which his nest was constructed when that tree is cut down by cruel men who are like death personified, and thus the bird achieves happiness in another place.

Purport:

Here the example is given of detachment from the bodily concept of life. The living entity resides within the body just as a bird dwells within a tree. When thoughtless men cut down the tree, the bird, without lamenting the loss of its previous nest, does not hesitate to establish its residence in another place.