Tosefta for Arakhin 11:17

[If] a Gentile dedicated a [cross-]beam to a synagogue, and there was written on it, "To the Name," we examine him [as to what is intended by the inscription]. If he said, I vowed it "To the Holy Name," we bury it, and if he said, I vowed it "To the Name of the Synagogue," we cut off the place [with the inscription of] "The Name" and bury that part, and it is permitted to use [the remainder]. [If the Gentile dedicated] sacred objects -- before they are used for a sacred purpose, they may be used for a non-sacred purpose, and objects that were used from the start for non-sacred purposes, we may not use them for sacred purposes. Stones and beams which were hewn from the start for an ordinary purpose may not be used to build on the Temple Mount. Stones [that had been used] for the Sanctuary or for the Temple Courtyard, which were damaged [during the destruction of the Temple], cannot be redeemed and must be buried. Said Rabbi Yehuda, it so happened with Rabbi Elazar son of Rabbi Tzadok that he bought the Synagogue [built by] Alexandrians in Jerusalem (see Jastrow re: "אֲלֶכְסַנְדְּרִי"), and he did what he wanted with it. They did not prohibit using it except during the time that it was still called by its original name.