Markandeya Purana 2.62

2.62

tathāpi yatnaḥ kartavyo naraiḥ sarveṣu karmasu /
kurvan puruṣakārantu vācyatāṃ yāti no satām //

Having spoken thus he looked at them and spoke again, “Return, go to the hermitage, taking the young birds with you. Where these egg-born may have no fear of cat, or rat, of hawk or ichneumon, there let the birds be placed. O dvijas, what is the use of great care? All creatures are destroyed or preserved by their own actions, as have been these young birds. Nevertheless men must exert themselves in all matters; he who does a manly act gains commendation from us, the good.”