B.G 2.69

या निशा सर्वभूतानां तस्यां जागर्ति संयमी। यस्यां जाग्रति भूतानि सा निशा पश्यतो मुनेः ॥६९॥

Where it is night for all beings, there the self controlled is wide awake. Where the beings are awake, that is observed as night by the meditating monk.

Gīta Bhāshya 2.69

Sleeping are those who are unaware of the lord's form and characteristics. When normal beings interested in material topics are awake, it is like a night for a Jnāni. 'muni' - one who is engaged in meditation, i.e. remembering the lord. Muni observing the day as night is his accomplishment.

उक्तम् लक्षणं पिण्डीकृत्याह - या निशेति।

'yā nishā' verse describes the characteristics of a Sthitaprajna in a summarized form.

या सर्वभूतानां निशा परमेश्वरस्य रूपलक्षणा यस्यां सुप्तानीव न किञ्चित् जानन्ति तस्याम् इन्द्रिय संयमयुक्तः ज्ञानी जागर्ति सम्यगापरोक्ष्येण पश्यति परमात्मानम् इत्यर्थः। यस्यां विषयलक्षणायां भूतानि जाग्रति तस्यां निशायामिव सुप्तः प्रायः न जानाति।

'yā niśā sarvabhūtānāṁ' i.e. that which is night for all beings, means, sleeping are those who are unaware of the lord's form and characteristics even to a limited extent. The wise Jnāni, at the same time is awake with well established transcendental knowledge and sees the supreme lord. When normal beings interested in material topics are awake, it is like a night for a Jnāni; he being asleep and not being aware.

मत्तादिवद् गमनादिप्रवृत्तिः। तदुक्तम् -

Though such a person is purposeless like a drunk person, he exhibits conscious tendencies. Therefore, it is said:

"देहं तु तं न चरमम्", "देहोपि दैववशगः"

इति श्लोकाभ्याम्।

"But this physical body in not him", "the body is under the control of the lord"

-states Bhagavata verses (Bhagavata 3.28.37-38).

मननयुक्तो मुनिः। 'पश्यतः' इत्यस्य साधनमाह ॥६९॥

'muni' is the one who is engaged in meditation, i.e. remembering the lord. By stating 'paśyataḥ', i.e. he observes as night, his accomplishment is highlighted.

Gīta Tātparya 2.69

The self-controlled who is focussed on Brahman sees only him and nothing else, similar to a person seeing the wonderful object glowing in the night.

"देवेभ्योSन्ये यदा ब्रह्म पश्यन्त्यन्यन्न दृश्यते। निशायामिव सुव्यक्तं यथाSन्यैर्ब्रह्म नेयते॥ आश्चर्यवस्तुदृग्यद्वत् व्यक्तमन्यन्न पश्यति। ऐकाग्र्याद्वा सुखोद्रेकात् देवाः सूर्यवदेव च। प्रायशः सर्ववेत्तारः तत्रापि ह्युत्तरोत्तरम्॥"

इति ब्रह्मतर्के ॥६९॥

"If the supreme Brahman is seen by other than the Dēvas, they don't observe anything else. It is similar to a mesmerized person seeing the wonderful object in the night. Only the Brahman who is in the front is clearly visible, and everything else is not visible, because of their concentration of mind and being immersed in its bliss. The Dēvas, similar to the Sun, may see everything based on their hierarchy."

-stated thus in Brahmatarka.