पुत्रो विश्रवसः साक्षाद्भ्राता वैश्रवणस्य च।
इत्युक्त्वा दुर्लभान्प्राणान्मुमोच पतगेश्वरः॥
putro viśravasaḥ sākṣād bhrātā vaiśravaṇasya ca
ity uktvā durlabhān prāṇān mumoca patageśvaraḥ
putraḥ = son; viśravasaḥ = of Viśravā; sākṣāt = he is a direct; bhrātā = a brother; vaiśravaṇasya = of Kuvera; ca = and; iti = this much; uktvā = having spoken; durlabhān = which was so difficult to preserve; prāṇān = his life; mumoca = gave up; pataga-īśvaraḥ = the lord of the birds.
“He is a direct son of Viśravā and a brother of Kuvera...” Having spoken this much, the lord of the birds gave up his life which was so difficult to preserve.
1 Sampāti will later describe Rāvaṇa—putro viśravasaḥ sākṣād bhrātā vaiśravaṇasya ca / adhyāste nagarīṁ laṅkāṁ rāvaṇo nāma rākṣasaḥ: “He is a direct son of Viśravā and a brother of Kuvera. Rāvaṇa, the lord of the rākṣasas, resides in the city Laṅkā.” (Rāmāyaṇa 4.58.19) Note that the first line of this statement by Sampāti is identical to the last words of Jaṭāyu. [Pillai] Lokācārya was a great leader of the southern branch of the Rāmānuja-sampradāya
2 Rāmāyaṇa-bhūṣaṇa: durlabhān brūhi brūhīti pṛcchate rāmāya sākalyena vijñāpana-paryantaṁ prāṇa na sthitāḥ hanteti ṛṣiḥ śocati.
Jaṭāyu began to speak about Rāvaṇa’s lineage. According to Śrī [Pillai] Lokācārya, Jaṭāyu wanted to say:
adhyāste nagarīṁ laṅkāṁ rāvaṇo rākṣaseśvaraḥ
“Rāvaṇa, the lord of the rākṣasas, resides in the city Laṅkā.”
This is because this is what Sampāti will say later on [about Rāvaṇa].1
Durlabhān (“which was so difficult to preserve”) indicates that Sage Vālmīki laments while reporting that Jaṭāyu’s life-airs departed from his body before he could answer all the questions repeatedly posed by Lord Rāmacandra.2 [Jaṭāyu died before he could] mention Rāvaṇa’s [place of] residence and so on.