• śaraṇyaḥ — the best source of shelter
  From √śri + -ya (worthy of). The One who is, by His very nature, the proper object of śaraṇāgati. Compare BG 18.66 — Kṛṣṇa is the only one who can say mām ekaṁ śaraṇaṁ vraja. Pauṇḍraka in verse 6 demanded that Kṛṣṇa take śaraṇa of him; now the chapter returns the word to its proper bearer. Śaraṇyaḥ — Bhagavān, by definition.
• samprahasya — loudly laughing
  Absolutive of sam-pra-√has (to laugh fully). The Lord's laughter — first at Pauṇḍraka (verse 15), now at the kṛtyā. The laugh is the chapter's recurring sign of Bhagavān's untouchedness; danger is comic in His presence.
• mā bhaiṣṭa — do not fear
  Imperative phrase: mā (don't) + bhaiṣṭa (be afraid). The classic Vaiṣṇava abhaya-vacana. Gauḍīyas hear this phrase as the audible signature of Bhagavān's protection — every time it occurs in the Bhāgavata, deliverance follows in the same scene.
• avitā asmi — I will protect
  Periphrastic future of √av (to protect). First-person, decisive. The Lord does not say 'I might' or 'I will try'; He says 'I am the future-protector.' Gauḍīyas note the construction's force: the form leaves no aperture for failure.
• vaiklavyam — agitation
  From vi-klṛp (to be in disorder). The disturbance of mind. Gauḍīyas note: the Lord protects from vaiklavya as much as from the fire itself — calming the bhakta's mind is part of the rakṣaṇa, not separate from it.

• Where do my fears assume Kṛṣṇa is not capable or not interested?
• What changes when I take Him at His word: 'Do not fear; I shall protect you'?

A father at the dinner table looks up to see his children white with fear and says, smiling, 'Don't be afraid; I'm here.' The smile is not levity; it is the disclosure that the danger has no actual standing in the room where He sits.