Shloka 15
मानसतीर्थ-शौचप्रशंसा | Praise of the ‘Mental Tīrtha’ and the Marks of Purity
जो मनुष्य नित्य अग्निमें होम करता हुआ एक वर्षतक प्रति दूसरे दिन एक बार भोजन करता है तथा प्रतिदिन अग्निकी उपासनामें तत्पर रहकर नित्य सबेरे जागता है, वह अग्निष्टोम यज्ञका फल पाता है ।।
Bhīṣma uvāca: yo manuṣyo nityam agnau homaṃ kurvan ekavarṣaṃ yāvat pratyahaṃ dvitīyadine ekavāraṃ bhojanaṃ karoti tathā pratidinam agnyupāsane tatparaḥ san nityaṃ prātaḥ prabudhyate, sa agniṣṭoma-yajñasya phalaṃ prāpnoti. haṃsa-sārasa-yuktaṃ ca vimānaṃ labhate naraḥ; indraloke ca vasate vara-strībhiḥ samāvṛtaḥ.
毗湿摩说道：若有人满一年每日向圣火献供，隔日仅食一次，日日勤修对阿耆尼的礼敬，并恒常于黎明起身——此人所得功德等同于阿耆尼什多摩（Agniṣṭoma）大祭。据说他将获得以天鹅与鹤为驾的天车，并居于因陀罗天界，群美环侍。
भीष्म उवाच
Educational Q&A
Steady discipline—daily fire-offerings, regulated eating, dawn-rising, and devotion to Agni—can yield the same religious merit as a major Vedic sacrifice (Agniṣṭoma), emphasizing that sincere, sustained practice can substitute for costly ritual performance.
Bhishma is describing a specific year-long observance (austerity plus fire-worship) and then states its promised reward: the fruit of the Agniṣṭoma sacrifice and enjoyment in Indra’s heaven with a celestial vimāna.