Rūpānuga Tattwa Sāra Bujhite Akaṅkha Jāṅra
Prākṛtāprakṛta Rasa-tattwa-jñānera Abaśyakatā — One Must Understand Both Material and Spiritual Mellows
One who wishes to understand the truth of Śrīla Rūpa Gosvāmī's teachings must understand the rasas. The spiritual blissful rasas control all else. They are the great treasure of the Supreme Truth.
Not understanding the heart of the Vedas, the impersonalists search for the impersonal Brahman, which is the effulgence of the rasas. Yearning to find the shadow of the rasas, the yogīs practice yoga. Tricked into thinking they will find what is really in the rasas, the karmīs perform karma.
Vibhāva, anubhāva, sāttvika-bhāva, and sañcāri-bhāva become beautiful when they meet in sthāyi-bhāva. In sthāyi-bhāva is the the highest, eternal, most relishable spiritual bliss.
The material rasas described in material poetry are not spiritual or eternal. They are not eternal. They are like reflections in a mirror or mirages in a desert.