Following the example of the python, one should give up material endeavors and accept for one’s maintenance food that comes of its own accord, whether such food be delicious or tasteless, ample or meager.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
ग्रासं सुमृष्टं विरसं महान्तं स्तोकमेव वा । यदृच्छयैवापतितं ग्रसेदाजगरोऽक्रियः
grāsaṃ sumṛṣṭaṃ virasaṃ mahāntaṃ stokameva vā | yadṛcchayaivāpatitaṃ grasedājagaro'kriyaḥ
SB 11.8.2