O King, once a wasp forced a weaker insect to enter his hive and kept him trapped there. In great fear the weak insect constantly meditated upon his captor, and without giving up his body, he gradually achieved the same state of existence as the wasp. Thus one achieves a state of existence according to one’s constant concentration.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
कीटः पेशस्कृतं ध्यायन् कुड्यां तेन प्रवेशितः । याति तत्सात्मतां राजन् पूर्वरूपमसन्त्यजन्
kīṭaḥ peśaskṛtaṃ dhyāyan kuḍyāṃ tena praveśitaḥ | yāti tatsātmatāṃ rājan pūrvarūpamasantyajan
SB 11.9.23