गोविन्द भाष्य (श्रील बलदेव विद्याभूषण - अचिन्त्यभेदाभेद वेदान्त ब्रह्मसूत्र भाष्य सटीक)

Siddhānta (conclusion): In the following words the author of the sūtras gives
His conclusion.
Sūtra 3
taḍito 'dhi varuṇaḥ sambandhāt
taḍitaḥ—lightning; adhi—above; varuṇaḥ—Varuṇa; sambandhāt—because of
the relationship.
Varuṇaloka comes after lightning, for that is their relationship.
Purport by Śrīla Baladeva Vidyābhūṣaṇa
In the Chāndogya Upaniṣad (4.15.5) it is said:
candramaso vidyutam
"He leaves the moon and goes to lightning."
It is seen that the soul travels from lightning to Varuṇaloka. Why is that? The
sūtra explains, “sambandhāt", which means "for that is the relationship between
lighting and Varuṇaloka". First lightning is manifested, and then comes rain. In
the Śruti-śāstra it is said:
yathā hi viśālā vidyutas tīvra-stanita-nirghoṣā jīmūtodare n