Canto 3 -
Araṇya-kāṇḍa
Chapter 51: Jaṭāyu Fights with Rāvaṇa
Text 3.51.31
परेतकाले पुरुषो यत्कर्म प्रतिपद्यते।
विनाशायात्मनोऽधर्म्यं प्रतिपन्नोऽसि कर्म तत्॥
pareta-kāle puruṣo yat karma pratipadyate
vināśāyātmano ’dharmyaṁ pratipanno ’si karma tat
pareta-kāle = at the time of his death; puruṣaḥ = a man; yat = it is similar; karma = to the conduct; pratipadyate = resorts to; vināśāya = just to destroy; ātmanaḥ = yourself; adharmyam = an adhārmika; pratipannaḥ = resorted to; asi = you have; karma tat = conduct.
You have resorted to an adhārmika conduct just to destroy yourself. It is similar to the conduct a man resorts to at the time of his death.1
1 Rāmāyaṇa-bhūṣaṇa: yat karma yādṛśaṁ karma.
The “adhārmika conduct” referred to here is Rāvaṇa’s abduction of Sītā-devī.
In other words, by engaging in such an act, Rāvaṇa would certainly attain death without delay.