Caitanya-caritāmṛta 6.136
jīvera asthi-viṣṭhā dui — śaṅkha-gomaya śruti-vākye sei dui mahā-pavitra haya
[jeevera asthi-vishthaa dui — shankha-gomaya shruti-vaakye sei dui mahaa-pavitra haya]
Blended reading (Sanskrit + English inline)
jīvera asthi-viṣṭhā dui — śaṅkha-gomaya śruti-vākye sei dui mahā-pavitra haya
Caitanya Mahāprabhu continued, “Conchshells and cow dung are nothing but the bones and the stool of some living entities, but according to the Vedic version they are both considered very pure.
Purport
According to Vedic principles, bones and dung are generally considered very impure. If one touches a bone or stool, he must take a bath immediately. That is the Vedic injunction. Yet the Vedas also enjoin that a conchshell, although the bone of an animal, and cow dung, although the stool of an animal, are very much sanctified. Even though such statements appear contradictory, on the basis of the Vedic version we still accept the fact that conchshells and cow dung are pure and sanctified.
— A.C. Bhaktivedanta Swami Prabhupāda
My note
Source: vedabase.io