וְעָבְר֤וּ הָעֹֽבְרִים֙ בָּאָ֔רֶץ וְרָאָה֙ עֶ֣צֶם אָדָ֔ם וּבָנָ֥ה אֶצְל֖וֹ צִיּ֑וּן עַ֣ד קָבְר֤וּ אֹתוֹ֙ הַֽמְקַבְּרִ֔ים אֶל־גֵּ֖יא הֲמ֥וֹן גּֽוֹג׃
Und wenn die durchgehen, werden sie durch das Land gehen, und jeder sieht einen Menschen's Knochen, dann soll er ein Zeichen daran aufstellen, bis die Burier es im Tal von Hamon-gog begraben haben.
Mishnah Niddah
They are believed when they say, "we buried miscarriages there," or "we did not bury them." They are believed when they say concerning a beast whether it had given birth to a firstling or had not given birth to one. They are believed when giving information on the marking of graves. But they are not believed either in regard to overhanging branches, or protruding stones or a bet ha-peras. This is the general rule: in any matter in which they are under suspicion they are not believed.