• pāvanī — purifying
  Pāvana = purifier. The Bhāgavatam pattern: Bhagavān's kīrti purifies all who hear it (śravaṇaṁ kīrtanaṁ viṣṇoḥ). Sāndīpani is unwittingly prophesying the entire kīrtana-tradition that will follow.
• chandāṁsi — Vedic hymns
  Chandas = metered Vedic mantra. The hymns the guru just taught. He prays they remain fresh in his disciples' memory — though, as Gauḍīyas note, in Bhagavān the chandas were never not present.
• ayāta - yāmāni — ever fresh
  Compound: a + yāta-yāma — not (yet) gone-stale. Yāta-yāma is the technical term for stale water or stale verse. The guru's wish: may the chandas never go stale. Bhagavān's Veda is the source of all 'unstale.'
• iha paratra — in this life and the next
  Iha = here; paratra = beyond. Standard Vedic phrase for both worlds. The blessing covers all duration — Sāndīpani gives the maximal time-frame to his disciples.
• vīrau — O heroes
  Vīra = hero. The address-form Sāndīpani uses for departure. Heroes — because they have proven so in the Pañcajana / Yamarāja episode. The teacher has finally seen His students in action.

• What blessings have your teachers given that you have not yet asked to remain 'ever fresh'?
• Where could you ask explicitly for cross-lifetime spiritual memory?

Sāndīpani blesses the two: 'may your fame purify, may the Vedic hymns be ever fresh in your minds, here and hereafter.' He gives Bhagavān a benediction — the small lamp blessing the sun — and Bhagavān accepts it as gravely as if the lamp had something the sun did not.