אבן העזר קכ״בEven HaEzer 122

Se’if 1א׳

אָמַר לַסוֹפֵר וְלָעֵדִים לִכְתֹּב וְלַחְתֹּם וְלִתֵּן גֵּט לְאִשְׁתּוֹ, וְכָתְבוּ וְחָתְמוּ וְנָתְנוּ לָהּ, וְנִמְצָא פָּסוּל אוֹ שֶׁכְּתָבוּהוּ וְנֶאֱבַד, יְכוֹלִים לִכְתֹּב גֵּט אַחֵר. וְאִם לֹא נֶאֱבַד, וְהֵם מְסֻפָּקִים אִם הוּא כָּשֵׁר מִכַּמָּה חֻמְרוֹת שֶׁנָּהֲגוּ לְהַחֲמִיר, הֲרֵי עָשׂוּ שְׁלִיחוּתָם וְצָרִיךְ לַחֲזֹר הַבַּעַל לוֹמַר לָהֶם לִכְתֹּב וְלַחְתֹּם. הַגָּה: וְאִם הָעֵדִים רוֹצִים לִכְתֹּב אַחֵר וְלִתֵּן לָהּ שְׁנֵיהֶם, הָרְשׁוּת בְּיָדָם וְאֵין צְרִיכִים לִשְׁאֹל לַבַּעַל (תְּשׁוּבַת הָרַשְׁבָּ"א הוּבְאָה בַּבֵּית יוֹסֵף). לָכֵן אִם הַבַּעַל הוֹלֵךְ מֵהָעִיר, יֹאמַר שֶׁהוּא נוֹתֵן לָהֶם רְשׁוּת לִכְתֹּב וְלַחְתֹּם גֵּט מֵאֶחָד עַד מֵאָה עַד שֶׁיְּהֵא אֶחָד כָּשֵׁר בֵּין בִּכְתִיבָה בֵּין בַּחֲתִימָה לְדַעַת הָרַב שֶׁבָּעִיר בְּלִי שׁוּם פִּקְפּוּק, הַגָּה: וּלְכָל מִי שֶׁמַּרְאֶה אוֹתוֹ (סֵדֶר גִּטִּין). אֲבָל אִם הַבַּעַל בָּעִיר, אֵין לִסְמֹךְ עַל זֶה וְיֵשׁ לַבַּעַל לַחֲזֹר וּלְצַוּוֹת כָּל פַּעַם לָעֵדִים וְלַסוֹפֵר (בֵּית יוֹסֵף בְּשֵׁם ר"ת); וְכֵן נוֹהֲגִין שֶׁחוֹזֵר וּמְצַוֶּה כְּמוֹ בָּרִאשׁוֹנָה, גַּם מַקְנֶה לָהֶם הַקְּלָף וְהַדְּיוֹ אִם לֹא נִשְׁאַר לַסוֹפֵר מִמַּה שֶּׁהִקְנָה לוֹ בָּרִאשׁוֹנָה (כֵּן נִמְצָא בְּסֵדֶר גִּטִּין). וְיֵשׁ אוֹמְרִים הָא דְּאָמְרִינַן עָשׂוּ עֵדִים וְסוֹפֵר שְׁלִיחוּתָן צָרִיךְ לַחֲזֹר וּלְצַוּוֹת, הַיְנוּ דַּוְקָא אִם כְּבָר נֶחְתַּם, וְנִפְסַל; אֲבָל אִם עֲדַיִן לֹא נֶחְתַּם, יְכוֹלִין לִכְתֹּב אַחֵר וְאֵין הַבַּעַל צָרִיךְ לְצַוּוֹת (בֵּית יוֹסֵף בְּשֵׁם הָרשב"ץ), אֲבָל נָהֲגוּ לְהַחֲמִיר בְּכָל עִנְיָן:

If he said to the scribe and to the witnesses to write and sign and deliver a bill of divorce to his wife, and they wrote and signed and delivered it, and it is found to be invalid or it was written and lost, they may write a new bill of divorce. If it was not lost, and they are unsure whether it is valid based on some stringencies regarding which they were accustomed to being stringent, they have fulfilled their mission and must return to the husband, who can then tell them to write and sign [a new bill of divorce]. Rem"a: If the witnesses want to write a new [bill of divorce] and both would deliver it to her, they have permission and need not ask the husband (Responsa of Rashb"a cited in the Beit Yosef). Therefore if the husband leaves the city, he should say that he gives them permission to write and sign anywhere from one to one hundred bills of divorce until one is valid both in its content and its signatures according to the Rabbi of the city beyond any doubt. Rem"a: And according to anyone who displays it (Seder Gitin). But if the husband is in town, one must not rely on this and the husband may go back and command the witnesses and the scribe each time [the bill of divorce needs to be rewritten] (Beit Yosef citing Rabbeinu Tam). Such is our custom, that [the husband] goes back and commands as he did originally, and also gives them the parchment and the ink if the scribe does not have any left over from that which he gave him originally (this is found in Seder Gitin). Some say that that which we say, "The witnesses and scribe fulfilled their mission, [so the husband] must go back and command them again," only applies is it was already signed and invalidated. If, however, it still has not been signed, they may write a new one and the husband need not command it (Beit Yosef citing the Rashba"tz), but the custom is to be stringent on all issues.

Se’if 2ב׳

אָמַר לָהֶם: כִּתְבוּ וְחִתְמוּ וּתְנוּ לְשָׁלִיחַ וְיוֹלִיךְ לָהּ, וְכָתְבוּ וְנָתְנוּ לְשָׁלִיחַ וְנִמְצָא הַגֵּט פָּסוּל אוֹ בָּטֵל, אֵין כּוֹתְבִין גֵּט אַחֵר עַד שֶׁיִּמָּלְכוּ בַּבַּעַל. וְאִם לֹא נִמְלְכוּ בּוֹ וְכָתְבוּ גֵּט אַחֵר כָּשֵׁר וּנְתָנוּהוּ לְשָׁלִיחַ וּנְתָנוֹ לָהּ, הֲרֵי זוֹ סָפֵק מְגֹרֶשֶׁת. הַגָּה: וְיֵשׁ אוֹמְרִים דְּכָל שֶׁנִּמְצָא הַגֵּט בָּטֵל אוֹ פָּסוּל כּוֹתְבִין גֵּט אַחֵר, אֶלָּא שֶׁאִם נֶאֱבַד מִיַּד הַשָּׁלִיחַ דִּינוֹ כְּמוֹ שֶׁנִּתְבָּאֵר (טוּר). וְכָל זֶה שֶׁאָמַר לָהֶם לִכְתֹּב וְלִתֵּן, אֲבָל נָתַן לַשָּׁלִיחַ גֵּט לְהוֹלִיכוֹ וְנִמְצָא פָּסוּל, פְּשִׁיטָא שֶׁאֵינָן יְכוֹלִין לִכְתֹּב אַחֵר בְּלֹא רְשׁוּת שֶׁלּוֹ (בֵּית יוֹסֵף בְּשֵׁם תְּשׁוּבַת הָרַשְׁבָּ"א, וְכֵן מַשְׁמַע מִתְּשׁוּבַת הָרַמְבַּ"ן סִימָן קמ"ה):

If he wrote for them, "Write [the bill of divorce], sign it, and give it to a messenger and he will take it to her," and they wrote it and gave it to a messenger and the bill of divorce was found to be invalid or nullified, they do not write a new bill of divorce until they confirm with the husband. If they did not confirm with him and they wrote a new, valid bill of divorce and gave it to the messenger and he gave it to her, it is doubtful whether she is divorced. Rem"a: There are those who say that whenever the bill of divorce is found to be nullified or invalid they write a new bill of divorce, but if the messenger lost it, the law is as has been explained (Tur). All this applies when he told them to write it and deliver it, but if he gave a bill of divorce to a messenger to bring it and it was found to be invalid, it is clear that they cannot write a new one without his permission (Beit Yosef citing Responsa of the Rashb"a, and also implied in Responsa of the Ramba"n #145).