SB 9.4.68
sadhavo hrdayam mahyam
sadhunam hrdayam tv aham
mad-anyat te na jananti
naham tebhyo manag api
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The pure devotee is always within the core of My heart, and I am always in the heart of the pure devotee. My devotees do not know anything else but Me, and I do not know anyone else but them.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Since Durvasa Muni wanted to chastise Maharaja Ambarisa, it is to be understood that he wanted to give pain to the heart of the Supreme Personality of Godhead, for the Lord says, sadhavo hrdayam mahyam: “The pure devotee is always within the core of My heart.” The Lord’s feelings are like those of a father, who feels pain when his child is in pain. Therefore, offenses at the lotus feet of a devotee are serious. Caitanya Mahaprabhu has very strongly recommended that one not commit any offense at the lotus feet of a devotee. Such offenses are compared to a mad elephant because when a mad elephant enters a garden it causes devastation. Therefore one should be extremely careful not to commit offenses at the lotus feet of a pure devotee. Actually Maharaja Ambarisa was not at all at fault; Durvasa Muni unnecessarily wanted to chastise him on flimsy grounds. Maharaja Ambarisa wanted to complete the Ekadasi-parana as part of devotional service to please the Supreme Personality of Godhead, and therefore he drank a little water. But although Durvasa Muni was a great mystic brahmana, he did not know what is what. That is the difference between a pure devotee and a so-called learned scholar of Vedic knowledge. The devotees, being always situated in the core of the Lord’s heart, surely get all instructions directly from the Lord, as confirmed by the Lord Himself in Bhagavad-gita (10.11):
tesam evanukampartham
aham ajñanajam tamah
nasayamy atma-bhavastho
jñana-dipena bhasvata
“Out of compassion for them, I, dwelling in their hearts, destroy with the shining lamp of knowledge the darkness born of ignorance.” The devotee does not do anything not sanctioned by the Supreme Personality of Godhead. As it is said, vaisnavera kriya mudra vijñeha na bujhaya. Even the most learned or experienced person cannot understand the movements of a Vaisnava, a pure devotee. No one, therefore, should criticize a pure Vaisnava. A Vaisnava knows his own business; whatever he does is precisely right because he is always guided by the Supreme Personality of Godhead.