SB 4.27.24

ṛṣabhaṁ yavanānāṁ tvāṁ
 vṛṇe vīrepsitaṁ patim
saṅkalpas tvayi bhūtānāṁ
 kṛtaḥ kila na riṣyati
Word for word: 
ṛṣabham — the best; yavanānām — of the untouchables; tvām — you; vṛṇe — I accept; vīra — O great hero; īpsitam — desired; patim — husband; saṅkalpaḥ — the determination; tvayi — unto you; bhūtānām — of all living entities; kṛtaḥ — if done; kila — certainly; na — never; riṣyati — becomes baffled.
Translation: 
Approaching the King of the Yavanas, Kālakanyā addressed him as a great hero, saying: My dear sir, you are the best of the untouchables. I am in love with you, and I want you as my husband. I know that no one is baffled if he makes friends with you.
Purport: 

The words yavanānām ṛṣabham refer to the King of the Yavanas. The Sanskrit words yavana and mleccha apply to those who do not follow the Vedic principles. According to the Vedic principles, one should rise early in the morning, take bath, chant Hare Kṛṣṇa, offer maṅgala-ārati to the Deities, study Vedic literature, take prasāda and engage in dressing and decorating the Deities. One must also collect money for the temple expenditures, or if one is a householder he must go to work in accordance with the prescribed duties of a brāhmaṇa, kṣatriya, vaiśya or śūdra. In this way one should live a life of spiritual understanding, and this is the Vedic way of civilization. One who does not follow all these rules and regulations is called a yavana or mleccha. One should not mistakenly think that these words refer to certain classes of men in other countries. There is no question of limitation according to nationalism. Whether one lives in India or outside of India, he is called a yavana or mleccha if he does not follow the Vedic principles. One who does not actually follow the hygienic principles prescribed in the Vedic rules and regulations will be subjected to many contagious diseases. Because the students in this Kṛṣṇa consciousness movement are advised to follow the Vedic principles, they naturally become hygienic.

If a person is Kṛṣṇa conscious, he can work like a young man even if he is seventy-five or eighty years old. Thus the daughter of Kāla (Time) cannot overcome a Vaiṣṇava. Śrīla Kṛṣṇadāsa Kavirāja Gosvāmī engaged in writing Caitanya-caritāmṛta when he was very old, yet he presented the most wonderful literature about the activities of Lord Caitanya. Śrīla Rūpa Gosvāmī and Sanātana Gosvāmī began their spiritual lives at a very old age — that is, after they retired from their occupations and family lives — yet they presented many valuable literatures for the advancement of spiritual life. This is confirmed by Śrīla Śrīnivāsa Ācārya, who praised the Gosvāmīs in this way:

nānā-śāstra-vicāraṇaika-nipuṇau sad-dharma-saṁsthāpakau
 lokānāṁ hita-kāriṇau tri-bhuvane mānyau śaraṇyākarau
rādhā-kṛṣṇa-padāravinda-bhajanānandena mattālikau
 vande rūpa-sanātanau raghu-yugau śrī-jīva-gopālakau

“I offer my respectful obeisances unto the Six Gosvāmīs, namely Śrī Sanātana Gosvāmī, Śrī Rūpa Gosvāmī, Śrī Raghunātha Bhaṭṭa Gosvāmī, Śrī Raghunātha dāsa Gosvāmī, Śrī Jīva Gosvāmī and Śrī Gopāla Bhaṭṭa Gosvāmī, who are very expert in scrutinizingly studying all the revealed scriptures with the aim of establishing eternal religious principles for the benefit of all human beings. Thus they are honored all over the three worlds, and they are worth taking shelter of because they are absorbed in the mood of the gopīs and are engaged in the transcendental loving service of Rādhā and Kṛṣṇa.”

Thus jarā, the effect of old age, does not harass a devotee. This is because a devotee follows the instructions and the determination of Nārada Muni. All devotees are in the disciplic succession stemming from Nārada Muni because they worship the Deity according to Nārada Muni’s direction, namely the Nārada-pañcarātra, or the pāñcarātrika-vidhi. A devotee follows the principles of pāñcarātrika-vidhi as well as bhāgavata-vidhi. Bhāgavata-vidhi includes preaching work — śravaṇaṁ kīrtanaṁ viṣṇoḥ — the hearing and chanting of the glories of Lord Viṣṇu, the Supreme Personality of Godhead. The pāñcarātrika-vidhi includes arcanaṁ vandanaṁ dāsyaṁ sakhyam ātma-nivedanam. Because a devotee rigidly follows the instructions of Nārada Muni, he has no fear of old age, disease or death. Apparently a devotee may grow old, but he is not subjected to the symptoms of defeat experienced by a common man in old age. Consequently, old age does not make a devotee fearful of death, as a common man is fearful of death. When jarā, or old age, takes shelter of a devotee, Kālakanyā diminishes the devotee’s fear. A devotee knows that after death he is going back home, back to Godhead; therefore he has no fear of death. Thus instead of depressing a devotee, advanced age helps him become fearless and thus happy.