CC Madhya 13.140
yatna kari, nāri kāḍhibāre
tāre dhyāna śikṣā karāha, loka hāsāñā māra,
sthānāsthāna nā kara vicāre
citta kāḍhi’ — withdrawing the consciousness; tomā haite — from You; viṣaye — in mundane subject matters; cāhi — I want; lāgāite — to engage; yatna kari — I endeavor; nāri kāḍhibāre — I cannot withdraw; tāre — to such a servant; dhyāna — of meditation; śikṣā — instruction; karāha — You give; loka — people in general; hāsāñā — laugh; māra — You kill; sthāna-asthāna — proper or improper place; nā kara — You do not make; vicāre — consideration.
Caitanya Mahāprabhu continued, “I would like to withdraw My consciousness from You and engage it in material activities, but even though I try, I cannot do so. I am naturally inclined to You only. Your instructions for Me to meditate on You are therefore simply ludicrous. In this way, You are killing Me. It is not very good for You to think of Me as a candidate for Your instructions.
Śrīla Rūpa Gosvāmī says in his Bhakti-rasāmṛta-sindhu (1.1.11):
ānakūlyena kṛṣṇānu- śīlanaṁ bhaktir uttamā
For a pure devotee, there is no scope for indulgence in mystic yoga practice or the cultivation of speculative philosophy. It is indeed impossible for a pure devotee to engage his mind in such unwanted activities. Even if a pure devotee wanted to, his mind would not allow him to do so. That is a characteristic of a pure devotee — he is transcendental to all fruitive activity, speculative philosophy and mystic yoga meditation. The gopīs therefore expressed themselves as follows.