In Bhagavad-gītā (18.5) Lord Kṛṣṇa says:
na tyājyaṁ kāryam eva tat
yajño dānaṁ tapaś caiva
“Acts of sacrifice, charity and penance are not to be given up but should be performed. Indeed, sacrifice, charity and penance purify even the great souls.”
Even one who has renounced the world and has taken sannyāsa should not renounce chanting the Hare Kṛṣṇa mahā-mantra. Renunciation does not mean that one has to renounce saṅkīrtana-yajña. Similarly, one should not renounce charity or tapasya. The yoga system for control of the mind and senses must be strictly followed. Lord Ṛṣabhadeva showed how severe types of tapasya could be performed, and He set an example for all others.