CC Ādi 17.269
bhikṣā karāiyā tāṅre kaila nivedana
According to the system of Vedic society, whenever an unknown sannyāsī comes to a village or town, someone must invite him to take prasādam in his home. Sannyāsīs generally take prasādam in the house of a brāhmaṇa because the brāhmaṇa worships the Lord Nārāyaṇa śilā, or śālagrāma-śilā, and therefore there is prasādam that the sannyāsī may take. Keśava Bhāratī accepted the invitation of Śrī Caitanya Mahāprabhu. Thus the Lord had a good opportunity to explain His desire to take sannyāsa from him.