Gitin6: 6
מִי שֶׁהָיָה מֻשְׁלָךְ לַבּוֹר, וְאָמַר כָּל הַשּׁוֹמֵעַ אֶת קוֹלוֹ יִכְתֹּב גֵּט לְאִשְׁתּוֹ — הֲרֵי אֵלּוּ יִכְתְּבוּ וְיִתְּנוּ.  הַבָּרִיא שֶׁאָמַר: ,,כִּתְבוּ גֵט לְאִשְׁתִּי”, רָצָה לְשַׂחֶק בָּהּ. מַעֲשֶׂה בְּבָרִיא אֶחָד שֶׁאָמַר: ,,כִּתְבוּ גֵט לְאִשְׁתִּי”, וְעָלָה לְרֹאשׁ הַגַּג, וְנָפַל וָמֵת. אָמַר רַבָּן שִׁמְעוֹן בֶּן גַּמְלִיאֵל: אָמְרוּ חֲכָמִים: אִם מֵעַצְמוֹ נָפַל — הֲרֵי זֶה גֵּט; אִם הָרוּחַ דְּחָאַתּוּ — אֵינוֹ גֵט.
[If] someone was thrown into a pit, and he said that whoever hears his voice should write a get for his wife, they shall write and give [it].  [If] a healthy man said: “Write a get for my wife,” he desired to taunt her. It happened that a healthy man said: “Write a get for my wife,” and he went up to the top of the roof, and he fell and died. Said Rabban Shimon ben Gamliel: The Sages said: If he fell on his own, it is a get; if the wind pushed him, it is not a get.