CC Ādi 4.273

ei ta’ kariluṅ ṣaṣṭha ślokera vyākhyāna
śrī-rūpa-gosāñira pāda-padma kari’ dhyāna
Word for word: 
ei ta’ — thus; kariluṅ — I have made; ṣaṣṭha ślokera — of the sixth verse; vyākhyāna — explanation; śrī-rūpa — Śrīla Rūpa Gosvāmī; gosāñira — of the master; pāda-padma — lotus feet; kari’ — doing; dhyāna — meditation.
Translation: 
Meditating on the lotus feet of Śrī Rūpa Gosvāmī, I have thus explained the sixth verse.