Taittirīyopaniṣat 01.22
अहं वृक्षस्य रेरिवा। कीर्तिः पृष्ठं गिरेरिव। ऊर्ध्वपवित्रो वाजिनीवस्वमृतमस्मि। द्रविणगं सवर्चसम्। सुमेधा अमृतोक्षितः। इति त्रिशङ्कोर्वेदानुवचनम् ॥२२॥
"I am the essence of the tree (of worldly existence); my fame is as the mountain's summit. I got purified and got elevated by the swift horse Vājinīvasu, (i.e. the one whose wealth is horses, i.e. Lord Vishnu abiding in the Sun). Because of which I have become immortal, wealthy, radiant, wise, and anointed with nectar" - Thus is the Vedic utterance of Triśaṅku.
Taittirīya Bhāshya 01.22
Testimonial from an ancient text, Yajuḥ-viveka is referenced to understand the above ecstatic utterance of King Triśaṅku, descendant of Manu, after he gets liberated by the grace of supreme Lord Hari. The cryptic word 'Vājinīvasu' i.e. the one whose wealth is horses, here refers to Lord Vishnu who abides in the Sun, possessor of swift horses.
"संसारवृक्षच्छेत्ताऽहं मत्कीर्तिः पर्वतोपमा। अत्युत्कृष्टेन हरिणा पावितोऽस्मि यतः स्फुटम्॥"
I am the one who has cut down the tree of worldly existence; my fame is as great as a mountain. I have been purified by the supreme Lord Hari, and clearly this is evident.
"वाजिरूपश्च नेता च वाजिनीः सूर्य उच्यते। तत्रस्थो भगवान् विष्णुः सम्प्रोक्तो वाजिनीवसुः॥"
The Sun, in the form of a horse and as a leader, is called the possessor of horses. There, the Lord Viṣṇu, abiding in it, is said to be Vājinīvasu, i.e. the one whose wealth is horses.
"तेनामृतोऽस्मि द्रविणं नित्यानन्दस्वरूपतः। तेनामृतेन सिक्तोऽहं तेन व्याप्तो यतस्सदा॥"
Because of that, I am immortal, and my wealth is of the nature of eternal bliss; by that immortality I am moistened, and by that I am always pervaded.
"इत्याह मन्त्रदृक् पूर्वं त्रिशङ्कुर्मानवो नृपः॥"
"Thus, the seer of mantras, King Triśaṅku, descendant of Manu, spoke in earlier times."
इति यजुर्विवेके॥
- stated thus in the ancient text Yajuḥ-viveka, the discernment of the Yajur.
