Sūtra 1.3.7

Sanskrit text, Unicode transliteration, Word-for-word and English translation of Sūtra 1.3.7:

स्थित्य्-अदनाभ्यां च

sthity-adanābhyāṃ ca

sthiti – staying; adanābhyāṃ – eating; ca – and.

“And also because one is eating and the other standing.” (7)

Sūtra pagination:
Adhyāya 1:
  The subject matter of all Vedic literatures is Brahman;
Pāda 3:
  Scriptural Texts that may Seem to Describe the Jīva or some other Topic, but in Truth Describe the Supreme Personality of Godhead.;
Adhikaraṇa 1:
  The Supreme Personality of Godhead is the Abode of Heaven.

Baladeva Vidyābhūṣaṇa’s commentary (Govinda-bhāṣya)

After describing the “abode of heaven and earth,” the Muṇḍaka Upaniṣad [3.1.1] goes on to say:

द्वा सुपर्णा सयुजा सखाया
समानं वृक्षं परिषस्वजाते
तयोर् अन्यः पिप्पलं स्वाद्य् अत्ति
अनश्नन्न् अन्यो ‘भिचाकशीति

dvā suparṇā sayujā sakhāyā
samānaṃ vṛkṣaṃ pariṣasvajāte
tayor anyaḥ pippalaṃ svādy atti
anaśnann anyo ‘bhicākaśīti

“Two friendly birds stay on the same tree. One eats the sweet pippala fruits and the other, not eating, shines with great splendor.”

If the “abode of heaven and earth” had not been previously mentioned then there would be no reason to assume that the splendid bird here is the Supreme Personality of Godhead. Otherwise if the “abode of heaven and earth” had not been mentioned, the sudden, unannounced mention of the Supreme Personality of Godhead in the allegory of the two birds would not be understandable. The Upaniṣad did not need to mention the jīva, who is already well known in the world, in the same way. For all these reasons, the “abode of heaven and earth” here refers to the Supreme Personality of Godhead.