तत्र स्नात्वा नरो राजन्सोपवासो जितेन्द्रियः । अश्वमेधस्य महतोऽसंशयं फलमाप्नुयात्
tatra snātvā naro rājansopavāso jitendriyaḥ | aśvamedhasya mahato'saṃśayaṃ phalamāpnuyāt
Ô Roi, l’homme qui s’y baigne, jeûnant et maître de ses sens, obtient sans nul doute le fruit du grand sacrifice de l’Aśvamedha.
Unspecified in the snippet (narrator addressing a king)
Tirtha: Kapilā–Viśalyā tīrtha (implied)
Type: sangam
Listener: King
Scene: A pilgrim at dawn performs snāna at a sacred confluence, hands joined in añjali; nearby a king listens to a sage describing the Aśvamedha-like fruit; the atmosphere is austere and pure.
Tīrtha-snāna combined with fasting and self-restraint is equated with the highest Vedic sacrificial merit.
The tīrtha being described in Adhyāya 23—contextually the Viśalyā–Saṅgama/related river confluence.
Bathe at the tīrtha, observe upavāsa (fasting), and maintain sense-control (jitendriya).