Puṣkara-Śapatha Itihāsa (Agastya–Indra Dispute at the Tīrthas) | पुष्कर-शपथ-आख्यानम्
भीष्म उवाच मासार्धमासोपवासाद् यत् तपो मन्यते जन: । आत्मतन्त्रोपघाती यो न तपस्वी न धर्मवित्
bhīṣma uvāca māsa-ardha-māsa-upavāsād yat tapo manyate janaḥ | ātma-tantro-paghātī yo na tapasvī na dharma-vit ||
Bhīṣma berkata: “Wahai Raja, mereka yang mengira tapa hanyalah berpuasa setengah bulan atau sebulan, sesungguhnya menyiksa tubuhnya dengan sia-sia. Orang yang bertindak semaunya dan merusak diri demikian bukanlah pertapa sejati, dan bukan pula pengenal dharma.”
भीष्म उवाच
Bhishma teaches that austerity is not simply prolonged fasting; without right understanding and disciplined purpose, such fasting becomes self-harm and does not make one a true ascetic or a knower of dharma.
In the Anushasana Parva, Bhishma instructs King Yudhishthira on dharma. Here he critiques the popular notion that a fortnight- or month-long fast by itself constitutes tapas, emphasizing ethical discernment over mere bodily mortification.