Formerly, at the end of Dvāpara-yuga, all the cowherd men of Vṛndāvana had arranged to worship King Indra, but they gave this worship up, following the advice of Kṛṣṇa. Instead, they performed a ceremony whereby they worshiped the cows, brāhmaṇas and Govardhana Hill. At that time Kṛṣṇa expanded Himself and declared, “I am Govardhana Hill.” In this way He accepted all the paraphernalia and food offered to Govardhana Hill. It is stated in the Śrīmad-Bhāgavatam (10.24.26, 31-33):

pacyantāṁ vividhāḥ pākāḥ sūpāntāḥ pāyasādayaḥ
saṁyāvā-pūpa-śaṣkulyaḥ sarva-dohaś ca gṛhyatām

kālātmanā bhagavatā śakra-darpaṁ jighāṁsatā
proktaṁ niśamya nandādyāḥ sādhv agṛhṇanta tad-vacaḥ

tathā ca vyadadhuḥ sarvaṁ yathāha madhusūdanaḥ
vācayitvā svasty-ayanaṁ tad-dravyeṇa giri-dvijān

upahṛtya balīn sarvān ādṛtā yavasaṁ gavām
go-dhanāni puras-kṛtya giriṁ cakruḥ pradakṣiṇam

“ ‘Prepare very nice foods of all descriptions from the grains and ghee collected for the yajña. Prepare rice, dhal, then halavah, pakorā, purī and all kinds of milk preparations like sweet rice, sweetballs, sandeśa, rasagullā and lāḍḍu.’

“The Supreme Personality of Godhead, Kṛṣṇa, therefore advised the cowherd men to stop the Indra-yajña and begin the Govardhana-pūjā to chastise Indra, who was very much puffed up at being the supreme controller of the heavenly planets. The honest and simple cowherd men, headed by Nanda Mahārāja, accepted Kṛṣṇa’s proposal and executed in detail everything He advised. They performed Govardhana worship and circumambulation of the hill. According to the instruction of Lord Kṛṣṇa, Nanda Mahārāja and the cowherd men called in learned brāhmaṇas and began to worship Govardhana Hill by chanting Vedic hymns and offering prasādam. The inhabitants of Vṛndāvana assembled together, decorated their cows and gave them grass. Keeping the cows in front, they began to circumambulate Govardhana Hill.”