Kesuvos2: 6
שְׁתֵּי נָשִׁים שֶׁנִּשְׁבּוּ, זֹאת אוֹמֶרֶת: ,,נִשְׁבֵּיתִי, וּטְהוֹרָה אֲנִי”, וְזֹאת אוֹמֶרֶת: ,,נִשְׁבֵּיתִי, וּטְהוֹרָה אֲנִי” — אֵינָן נֶאֱמָנוֹת. וּבִזְמַן שֶׁהֵן מְעִידוֹת זוֹ אֶת זוֹ — הֲרֵי אֵלּוּ נֶאֱמָנוֹת.
[If] two women were captured, [and now] this one says: “I was captured, but I am undefiled,” and this one says: “I was captured, but I am undefiled,” they are not believed. [If] they testify for one another, however, these are believed.