פירוש על עבודה זרה 83:13

Again, we read a baraita which says that even if an Israelite breaks up a statue of Mercury (which was originally composed of stones) and uses it to pave a road, the stones and everything they were used to build is prohibited. This is a difficulty against Resh Lakish.
The Talmud resolves this by again citing Rava’s statement. In principle these stones were annulled because the idol was broken. However, we don’t allow people to use them lest the Jew come to own the idol, in which case it can’t be annulled. But if an idol broke on its own, it is annulled.