CC Madhya-lila 11.011 - Caitanya-candrodaya-nataka 8.24
Sri Caitanya-caritamrta
CC Madhya-lila
CC Madhya 11.11, Translation and Purport:
“"Just as one is immediately frightened upon seeing a live serpent or even the form of a serpent, one endeavoring for self-realization should similarly fear a materialistic person and a woman. Indeed, he should not even glance at their bodily features."
This is a quotation from Śrī Caitanya-candrodaya-nāṭaka (8.24).