prabhura - of Lord Śrī Caitanya Mahāprabhu; sannyāsa dekhi' - when he saw the sannyāsa order; unmatta hañā - he became just like a madman; sannyāsa grahaṇa kaila - he also accepted the renounced order of life; vārāṇasī - to Vārāṇasī; giyā - going.

After seeing that Śrī Caitanya Mahāprabhu accepted the renounced order, Puruṣottama Ācārya became like a madman and immediately went to Vārāṇasī to take sannyāsa.