• utthāya — having risen
  Absolutive of ut-√sthā. Mucukunda's ut-thāna prefigures the deeper ut-thāna of his consciousness: he rises from physical sleep, and within a few verses will rise from the sleep of material identification into bhakti.
• ciram — for a long time
  Marks the immensity of his sleep — yuga-spans, granted by the demigods. The Bhāgavata pacing slows here to honor it: a tapasvī who served Indra is now waking exactly when Kṛṣṇa is in the room. Kāla is Kṛṣṇa's instrument; the timing belongs to Him.
• śanaiḥ — slowly
  Adverb — gently, by degrees. The verse refuses to rush the waking; even narrative tempo reverences the ṛṣi. Gauḍīyas read this slowness as a counterweight to Kālayavana's frantic chase: bhakti-pace versus asura-pace.
• locane — his two eyes
  Dual of locana. These are the eyes whose glance will next combust the asura. The poet lingers on the opening of the eyes precisely because their darśana is, in the next verse, lethal — and elsewhere in the Bhāgavata redemptive.
• avasthitam — standing
  Past participle of ava-√sthā. Kālayavana is sthita in the wrong place at the wrong moment, while Kṛṣṇa has just entered and stepped aside. The verb-field of standing/lying frames the whole scene: the sleeper rises, the standing one falls.

A long-banked fire opens its eyes — the cave-darkness, then a figure standing too close. Mucukunda's slow waking is the universe drawing a breath before a verdict; the asura mistakes the sleeper for the disturber, and signs his own death warrant by being the first thing the sage sees.