Shloka 2
Adhyāya 51: Kṛṣṇa’s Leave-Taking and Departure for Dvārakā (द्वारकागमनानुमति)
अधिष्ठाता मनो नित्यं भूतानां महतां तथा । बुद्धिरैश्वर्यमाचष्टे क्षेत्रज्ञक्ष स उच्यते,उन पज्चमहाभूतोंका नित्य आधार भी मन ही है। बुद्धि जिसके ऐश्वर्यको प्रकाशित करती है, वह क्षेत्रज्ञ कहा जाता है
adhiṣṭhātā mano nityaṁ bhūtānāṁ mahatāṁ tathā | buddhir aiśvaryam ācāṣṭe kṣetrajñaḥ sa ucyate ||
ヴāユは言った。心は、偉大なる元素をも含む一切の存在にとって、常に統べる支えである。知性（ブッディ）が主宰の力と自在を顕すその原理は、「クシェートラジュニャ（場の知者）」と呼ばれる。
वायुदेव उवाच
Educational Q&A
The verse distinguishes inner faculties and points toward the kṣetrajña: mind functions as the constant presiding basis for embodied existence (even with respect to the great elements), while the conscious principle—known through the operation of buddhi that manifests mastery and discernment—is termed the Knower of the Field.
Vāyudeva is instructing the listener in a philosophical register, explaining how mind and intellect relate to embodied life and identifying the deeper conscious principle (kṣetrajña) that is to be understood as the true knower behind the psycho-physical field.