177 Yevamot 16/2-3

(ב) שְׁתֵּי יְבָמוֹת, זוֹ אוֹמֶרֶת מֵת בַּעְלִי וְזוֹ אוֹמֶרֶת מֵת בַּעְלִי, זוֹ אֲסוּרָה מִפְּנֵי בַעְלָהּ שֶׁל זוֹ וְזוֹ אֲסוּרָה מִפְּנֵי בַעְלָהּ שֶׁל זוֹ. לָזוֹ עֵדִים וְלָזוֹ אֵין עֵדִים, אֶת שֶׁיֶּשׁ לָהּ עֵדִים, אֲסוּרָה. וְאֶת שֶׁאֵין לָהּ עֵדִים, מֻתֶּרֶת. לָזוֹ בָנִים וְלָזוֹ אֵין בָּנִים, אֶת שֶׁיֶּשׁ לָהּ בָּנִים, מֻתֶּרֶת. וְאֶת שֶׁאֵין לָהּ בָּנִים, אֲסוּרָה. נִתְיַבְּמוּ וּמֵתוּ הַיְבָמִין, אֲסוּרוֹת לְהִנָּשֵׂא. רַבִּי אֶלְעָזָר אוֹמֵר, הוֹאִיל וְהֻתְּרוּ לַיְבָמִין, הֻתְּרוּ לְכָל אָדָם:

(ג) אֵין מְעִידִין אֶלָּא עַל פַּרְצוּף פָּנִים עִם הַחֹטֶם, אַף עַל פִּי שֶׁיֵּשׁ סִימָנִין בְּגוּפוֹ וּבְכֵלָיו. אֵין מְעִידִין אֶלָּא עַד שֶׁתֵּצֵא נַפְשׁוֹ, וַאֲפִלּוּ רָאוּהוּ מְגֻיָּד, וְצָלוּב, וְהַחַיָּה אוֹכֶלֶת בּוֹ. אֵין מְעִידִין אֶלָּא עַד שְׁלֹשָׁה יָמִים. רַבִּי יְהוּדָה בֶּן בָּבָא אוֹמֵר, לֹא כָל הָאָדָם וְלֹא כָל הַמָּקוֹם וְלֹא כָל הַשָּׁעוֹת שָׁוִין:

(2) [If] two Yevamot [a Yevama is a woman whose husband died childless and whose brother-in-law must marry or dismiss her, who are married to brothers come from overseas and] this one says, "My husband died" and this one says, "My husband died", this one is forbidden [to re-marry] because of the other one's husband, and this one is forbidden [to re-marry] because of the other one's husband. [If] this one has witnesses [that her husband died] and the other one has no witnesses [that her husband died], the one who has witnesses is forbidden [to re-marry], and the one who has no witnesses is permitted [to re-marry]. [If] this one has children and the other one has no children, the one who has children is permitted [to re-marry], and the one who has no children is forbidden [to re-marry]. [If] they undergo Yibum and the Yevamim [a Yavam is one upon whom has fallen the obligation to perform Levirate marriage] die they are forbidden to marry. Rabbi Elazar says: Since they were permitted to the Yevamim they are [later] permitted to any man.

(3) One may only testify [that somebody has died on the basis] of the face including the nose, even if there are [identifying] signs on his body and his clothes. One may only testify [that somebody has died] once his soul has departed, even if they see him dismembered, or crucified, or an animal eating him. One may only testify within three days [of death when he is still recognizable]. Rabbi Yehudah ben Bava says: Not all people, nor all places, nor all times are equal [that is, people decompose differently under different circumstances].