difficult to obtain — NoI 11plugin-autotooltip__small plugin-autotooltip_bigNectar of Instruction Text 11

Of the many objects of favored delight and of all the lovable damsels of Vrajabhūmi, Śrīmatī Rādhārāṇī is certainly the most treasured object of Kṛṣṇa's love. And, in every respect, Her divine kuṇḍa is described by great sages as similarly dear to Him. Undoubtedly Rādhā-kuṇḍa is very rarely attained even by the great devotees; therefore it is even more difficult for ordinary devotees to attain. If one simply bathes once within those holy waters, one's pure love of Kṛṣṇa is fully aroused.

very difficult to achieve — SB 5.3.17plugin-autotooltip__small plugin-autotooltip_bigŚrīmad Bhāgavatam 5.3.17

The Supreme Personality of Godhead replied: O great sages, I am certainly very pleased with your prayers. You are all truthful. You have prayed for the benediction of a son like Me for King Nābhi, but this is very difficult to obtain. Since I am the Supreme Person without a second and since no one is equal to Me, another personality like Me is not possible to find. In any case, because you are all qualified brāhmaṇas, your vibrations should not prove untrue. I consider the brāhmaṇas who are well qualified with brahminical qualities to be as good as My own mouth.