Because Madhavendra Puri was a senior sannyasi Vaisnava, a paramahamsa, the priest (of Gopinatha temple) immediately fell flat before him and offered obeisances
Hearing this invitation, Mādhavendra Purī came out and identified himself. The priest then delivered the pot of sweet rice and offered his obeisances, falling flat before him.
A brāhmaṇa is not supposed to offer his obeisances by falling flat before anyone because a brāhmaṇa is considered to be in the highest caste. However, when a brāhmaṇa sees a devotee, he offers his daṇḍavats. This brāhmaṇa priest did not ask Mādhavendra Purī whether he was a brāhmaṇa, but when he saw that Mādhavendra Purī was such a bona fide devotee that Kṛṣṇa would even steal for him, he immediately understood the position of the saint. As stated by Śrī Caitanya Mahāprabhu: kibā vipra, kibā nyāsī, śūdra kene naya/ yei kṛṣṇa-tattva-vettā, sei "guru" haya. (CC Madhya 8.128) Had the brāhmaṇa priest been an ordinary brāhmaṇa, Gopīnātha would not have talked with him in a dream. Since the Deity spoke to both Mādhavendra Purī and the brāhmaṇa priest in dreams, practically speaking they were on the same platform. However, because Mādhavendra Purī was a senior sannyāsī Vaiṣṇava, a paramahaṁsa, the priest immediately fell flat before him and offered obeisances.