Bhakti-rasāmṛta-sindhu .4.264
atyanta-kaṭhinaṁ vajram akutaścana mārdavam |
[atyanta-kathinam vajram akutashchana maardavam |]
īdṛśaṁ tāpasādīnāṁ cittaṁ tāvad avekṣyate ||264||
[eedrisham taapasaadeenaam chittam taavad avekshyate ||264||]
Blended reading (Sanskrit + English inline)
atyanta-kaṭhinaṁ vajram akutaścana mārdavam |
īdṛśaṁ tāpasādīnāṁ cittaṁ tāvad avekṣyate ||264||
The thunderbolt is extremely hard and never becomes soft. This hardness is seen in the hearts of those who perform severe austerities.
Purport
The lightning bolt is very strong and never becomes soft. Similarly, the hearts of those who are engaged in severe austerities and penances do not become very easily softened.
— A.C. Bhaktivedanta Swami Prabhupāda
Gauḍīya Ācāryas
Jīva Gosvāmī
Gauḍīya
Durgama-saṅgamanī
Commentary
Tāpasādīnām refers to immature devotees in śānta mood.
My note
Source: vedabase.io