Once upon a time, the cowherd men of Vṛndāvana, headed by Nanda Mahārāja, desired to go to Ambikāvana to observe the Śiva-rātri ceremony. The rāsa-līlā was performed during the autumn, and after that the next big ceremony is Holi, or the Dolāyātrā ceremony. Between the Dolāyātrā ceremony and the rāsa-līlā ceremony there is an important ceremony called Śiva-rātri, which is especially observed by the Śaivites, or devotees of Lord Śiva. Sometimes the Vaiṣṇavas also observe this ceremony because they accept Lord Śiva as the foremost Vaiṣṇava. But the function of Śiva-rātri is not observed very regularly by the bhaktas, or devotees of Kṛṣṇa. Under the circumstances, Śrīmad-Bhāgavatam states that Nanda Mahārāja and the other cowherd men "once upon a time desired." This means that they were not regularly observing the Śiva-rātri function but that once upon a time they wanted to go to Ambikāvana out of curiosity. Ambikāvana is somewhere in Gujarat Province, and it is said to be situated on the river Sarasvatī. Yet we do not find any Sarasvatī River in Gujarat Province, although there is a river named Savarmatī. In India, all the big places of pilgrimage are situated on nice rivers like the Ganges, Yamunā, Sarasvatī, Narmadā, Godāvarī and Kāverī. Ambikāvana was situated on the bank of the Sarasvatī, and Nanda Mahārāja and all the other cowherd men went there.
They very devotedly began to worship the deity of Lord Śiva and Ambikā. It is the general practice that wherever there is a temple of Lord Śiva, there must be another temple, of Ambikā (or Durgā), because Ambikā is the wife of Lord Śiva and is the most exalted of chaste women. She doesn’t live outside the association of her husband. After reaching Ambikāvana, the cowherd men of Vṛndāvana first bathed themselves in the river Sarasvatī. If one goes to any place of pilgrimage, his first duty is to take a bath and sometimes to shave his head. That is the first business. After taking a bath, they worshiped the deities and then distributed charity in the holy places.
According to the Vedic system, charity is given to the brāhmaṇas. It is stated in the Vedic śāstras that only the brāhmaṇas and the sannyāsīs can accept charity. The cowherd men from Vṛndāvana gave the brāhmaṇas cows decorated with golden ornaments and beautiful garlands. The brāhmaṇas are given charity because they are not engaged in any business profession. They are supposed to be engaged in brahminical occupations, as described in the Bhagavad-gītā—namely, they must be very learned and must perform austerity and penances. Not only must they themselves be learned, but they must also teach others. Brāhmaṇas are not meant to be brāhmaṇas alone: they should create other brāhmaṇas also. If a man is found who agrees to become a brāhmaṇa's disciple, he is also given the chance to become a brāhmaṇa. The brāhmaṇa is always engaged in the worship of Lord Viṣṇu. Therefore the brāhmaṇas are eligible to accept all kinds of charity. But if the brāhmaṇas receive excess charity, they are to distribute it for the service of Viṣṇu. In the Vedic scriptures, therefore, one is recommended to give charity to the brāhmaṇas, and by so doing one pleases Lord Viṣṇu and all the demigods.
The pilgrims take a bath, worship the deity and give charity; they are also recommended to fast one day. They should go to a place of pilgrimage and stay there at least for three days. The first day is spent fasting, and at night they can drink a little water because water does not break the fast.
The cowherd men, headed by Nanda Mahārāja, spent that night on the bank of the Sarasvatī. They fasted all day and drank a little water at night. But while they were taking rest, a great serpent from the nearby forest appeared before them and hungrily began to swallow up Nanda Mahārāja. Nanda cried out helplessly, "My dear son, Kṛṣṇa, please come and save me from this danger! This serpent is swallowing me!" When Nanda Mahārāja cried for help, all the cowherd men got up and saw what was happening. They immediately took up burning logs and began to beat the snake to kill it. But in spite of being beaten with burning logs, the serpent was not about to give up swallowing Nanda Mahārāja.