भस्महुतं पार्थ यथा तोयविवर्जितम् । निष्फलं जायते दानं तथा मन्त्रविवर्जितम्
bhasmahutaṃ pārtha yathā toyavivarjitam | niṣphalaṃ jāyate dānaṃ tathā mantravivarjitam
Ô Pārtha, de même qu’une offrande de cendre, privée d’eau, devient vaine, de même le dāna (don sacré) est sans fruit lorsqu’il est dépourvu de mantra.
Skanda (deduced; vocative suggests a dialogic address preserved in narration)
Listener: Pārtha (addressed)
Scene: A didactic tableau: a sage instructs a devotee; beside them, a ritual fire with an offering of ash shown as ineffective, contrasted with a proper libation with water and mantra; a donor offers gifts with a mantra-scroll or rosary indicating consecration.
Charity is sanctified and made efficacious through mantra; otherwise it is compared to a defective offering.
The broader teaching is embedded in the Revā Khaṇḍa’s Narmadā tīrtha narrative, though the point applies universally.
Perform dāna with mantra (and proper sanctifying procedure), not as a mantra-less act.