Lord Caitanya then told Sanātana Gosvāmī: "I was just like a madman in describing this ātmārāma verse in so many ways. Do not mind if I have said something mad. But if someone becomes a madman like Me, he can understand the real meaning of Śrīmad-Bhāgavatam as I have explained it."
Then Sanātana Gosvāmī, with folded hands, fell at the feet of Lord Caitanya and prayed as follows: "My dear Lord, You have asked me to prepare a book on the regulative principles of devotional service, but I belong to the lowest caste. I have no knowledge. I do not know how such an important task can be finished by me. If You will kindly give me some hints about the preparation of such a book on devotional service, it may be that I shall be qualified to write it."
The Lord then blessed him, saying, "By the grace of Kṛṣṇa, whatever you write will come out of your heart and be accepted. As you have requested, I will now give you some notes that you can take down. The first and foremost point is that one should accept a bona fide spiritual master. That is the beginning of spiritual life." Lord Caitanya then requested Sanātana Gosvāmī to write down the symptoms of a true guru and the symptoms of a true disciple. The symptoms of a guru are described in the Padma Purāṇa: "A person who is a qualified brāhmaṇa and at the same time has all the symptoms of a devotee can become a spiritual master for all classes of men. Such a devotee and spiritual master must be respected as God Himself. Even though a person may be born in a very respectable brāhmaṇa family, he cannot become a bona fide spiritual master if he is not a devotee of the Lord." One should not mistakenly think that a bona fide spiritual master has to be born in a so-called brāhmaṇa family. The idea is that a spiritual master must be a qualified brāhmaṇa; that is, he must be qualified by his activities.
This is confirmed in Śrīmad-Bhāgavatam, when Nārada speaks of the different symptoms characterizing the four divisions of social life. Nārada therein states that brāhmaṇas, kṣatriyas, vaiśyas and śūdras should be selected by their individual qualifications. In his commentary, Śrīdhara Svāmī has noted that birth in a family of brāhmaṇas does not necessarily mean that one is a brāhmaṇa. One must be qualified with a brāhmaṇa's symptoms, which are described in the śāstras. In the disciplic succession of the Gauḍīya Vaiṣṇava sampradāya, there are two great ācāryas (Ṭhākura Narottama and Śyāmānanda Gosvāmī) who were not born in brāhmaṇa families but were accepted as spiritual masters by many famous brāhmaṇas, including Gaṅgānārāyaṇa and Rāmakṛṣṇa.
In this way there are symptoms which both the prospective spiritual master and the prospective disciple must have, and both the disciple and the spiritual master must see whether the other is eligible to become either a bona fide spiritual master or a bona fide student. One should then know that the only worshipable object is the Supreme Personality of Godhead, and one should learn the various mantras and sacred songs.
The Lord then instructed Sanātana to describe the symptoms of those persons who are eligible to accept the mantras and to describe how the mantras should be understood and perfected by ritualistic performances. Then the Lord instructed Sanātana to describe initiation, morning duties and duties of cleanliness—washing the face, brushing the teeth, and so on—the process of work and the prayers to be recited both in the morning and the evening. The Lord also told him to describe how one should worship the spiritual master, how to mark one's body with gopī-candana, how to collect tulasī leaves, how to wash the room and temple of the Lord, and how to awaken Kṛṣṇa from sleep. Then Lord Caitanya instructed Sanātana to describe different methods for worshiping the Lord, with fivefold, sixteenfold or fiftyfold paraphernalia, how to worship the Lord by offering Him ārati five times a day, and how to offer food to Kṛṣṇa and lay Him down on His bed. Next Lord Caitanya instructed Sanātana to write about the characteristics of both the form of the Lord in the temple and the śālagrāma-śilā, and also to write about the effect of going to holy places where there are different temples of the Lord and seeing the form of God in the temple. Sanātana was also instructed to glorify the transcendental name of the Lord and to describe the different offenses one can commit while chanting the Lord's name or worshiping the Deity. In the worship of the Lord certain paraphernalia are used, such as a conchshell, water, incense and fragrant flowers. The Lord instructed Sanātana to describe these, along with the chanting of prayers and hymns, circumambulation, and the offering of obeisances. Other topics for Sanātana to explain included following the regulative principles of puraścaraṇa, accepting kṛṣṇa-prasādam, rejecting foodstuff not offered to Kṛṣṇa, and not indulging in defaming a devotee who has the actual symptoms of a devotee.
Lord Caitanya also instructed Sanātana to describe the symptoms of a holy man, the process of satisfying the sages, and the value of rejecting the society of undesirable persons and hearing Śrīmad-Bhāgavatam constantly. Also to be described were how to follow the daily, fortnightly and monthly duties, how to observe fasting on the Ekādaśī day, how to observe ceremonies like the birthday of the Lord, and how to observe fasting not only on Ekādaśī but also on Janmāṣṭamī, Vāmana-dvādaśī, Rāma-navamī and Nṛsiṁha-caturdaśī. Lord Caitanya also instructed Sanātana to explain that it is helpful in the advancement of devotional service to avoid fast days that overlap with other days (viddhā). Also to be explained were how to establish temples of the Lord, along with the general behavior, symptoms, duties and occupation of a Vaiṣṇava. And at every step, Lord Caitanya said, Sanātana Gosvāmī should give documentary evidence from the purāṇas. Thus the Lord gave a summary of all the topics Sanātana should include in his book on Vaiṣṇava regulative principles.
Sanātana Gosvāmī was a great devotee of the Lord, and he was directly instructed to spread the cult of bhakti by writing many books. There is a description of Sanātana in the Caitanya-candrodaya, where it is said that Sanātana Gosvāmī was one of the most important personalities in the government of Nawab Hussain Shah. Sanātana's brother, Rūpa Gosvāmī, was also a minister in the government, but both of them gave up their lucrative government posts to become mendicants and serve the Supreme Lord. Externally the brothers became just like ordinary mendicants, but their hearts were filled with transcendental loving service and a great love for the cowherd boy of Vṛndāvana. Indeed, Sanātana Gosvāmī was dear to all pure devotees of his time.