Reference for Avodah Zarah 98:22

If somebody finds an idol, Rav said, he breaks it limb by limb and it becomes insignificant, but Samuel said, it never can become insignificant⁷⁶Rav holds that an idol broken into little pieces cannot be reconstituted. Therefore it is no longer an idol and the shards may be used. Samuel holds that an idol which falls into the hands of a Jew is ḥerem and forbidden for any use under any circumstance (Deut. 13:18). For him the only way an idol or its parts can become useable for a Jew is that a Gentile (a pagan) breaks it. The Babli (49b) explains Samuel’s position away..