Mahabharata — Ashvamedhika Parva, Shloka 9
Mind as Charioteer; Kṣetrajña, Tapas, and Dhyāna-Yoga
Adhyātma-Upadeśa
व्याख्यातं पूर्वकल्पेन मशकोदुम्बरं यथा । भुज्यमानं न जानीते नित्यं सत्त्वमचेतनम् । यस्त्वेवं तं विजानीते यो भुड्धक्ते यश्व भुज्यते
vyākhyātaṃ pūrvakalpena maśakodumbaraṃ yathā | bhujyamānaṃ na jānīte nityaṃ sattvam acetanam | yas tv evaṃ taṃ vijānīte yo bhoktā caiva bhujyate ||
风神说道：“正如先前以蚊与优昙婆罗（udumbara，丛生无花果）为喻所阐明的，那被‘享受’的原则——无觉的萨特瓦——并不能真正认识永恒的知田者。然而知田者（kṣetrajña）却能如实了知：受用者是自我，而所受用者是物质之质（sattva）。”
वायुदेव उवाच
Educational Q&A
It distinguishes the conscious experiencer (ātman/kṣetrajña, the bhoktā) from the insentient experienced field or quality (sattva, the bhogya). True knowledge is recognizing that the Self is the knower and enjoyer, while material nature is what is enjoyed.
Vāyu continues a philosophical instruction, referring back to an earlier analogy (mosquito and udumbara) to clarify how the insentient cannot know the eternal knower, whereas the knower correctly discerns the relation between experiencer and experienced.