אבן העזר קכ״אEven HaEzer 121

Se’if 1א׳

צָרִיךְ שֶׁיִּהְיֶה בְּדַעְתּוֹ בְּשָׁעָה שֶׁמְּצַוֶּה לְכָתְבוֹ. לְפִיכָךְ, אִם אֲחָזוֹ רוּחַ רָעָה בְּשָׁעָה שֶׁמְּצַוֶּה לְכָתְבוֹ, אֵין כּוֹתְבִין אוֹתוֹ אֲפִלּוּ לִכְשֶׁיַּבְרִיא. וְכֵן הַשִּׁכּוֹר, שֶׁהִגִּיעַ לְשִׁכְרוּתוֹ שֶׁל לוֹט, וְאָמַר: כִּתְבוּ, אֵין כּוֹתְבִין. וְאִם לֹא הִגִּיעַ, הֲרֵי זֶה סָפֵק:

The husband must be of sound mind when he orders [the writ of divorce] to be written. Therefore, if he was seized by melancholy when he gave the order we do not write it, even after he is well. Similarly, a drunk person, if he reached the level of Lot's intoxication, and he said, "write it!" we do not write it. If he did not reach [that level of intoxication], this is a case of doubt.

Se’if 2ב׳

הָיָה בָּרִיא בְּשָׁעָה שֶׁצִּוָּה לְכָתְבוֹ, וְאַחַר כָּךְ אֲחָזוֹ הַחֹלִי, אֵין כּוֹתְבִים אוֹתוֹ בְּעוֹדוֹ בְּחָלְיוֹ. וְאִם כְּתָבוּהוּ וּנְתָנוּהוּ קֹדֶם שֶׁיַּבְרִיא, אִם הוּא חֹלִי דְּסַמֵּהּ בִּידָן, הֲרֵי זֶה פָּסוּל; וְאִם לָאו, אֵינוֹ גֵּט. הַגָּה: אֲבָל לְאַחַר שֶׁנִּתְרַפֵּא, כּוֹתְבִין וְנוֹתְנִין, אֲפִלּוּ מִחָה בְּחָלְיוֹ שֶׁלֹּא לִתְּנוֹ (טוּר):

If he was well when he ordered the writing, and then he suffered [mental] illness, we do not write it while he is still ill. If they did write and give it [to his wife] before he recovered, if his illness is readily treatable, the writ is disqualified. If not, it is not a writ. Rem"a: But after he recovers, we write it and give it, even if he protested during his illness and said that we should not give it.

Se’if 3ג׳

מִי שֶׁהוּא עִתִּים חָלִים (פֵּרוּשׁ, בָּרִיא, מִן "וְתַחֲלִימֵנִי וְהַחֲיֵינִי" (יְשַׁעְיָה לח, טז עִתִּים שׁוֹטֶה, כְּשֶׁהוּא חָלִים, הֲרֵי הוּא כְּפִקֵּחַ לְכָל דְּבָרָיו. וְאִם גֵּרַשׁ בְּאוֹתָהּ שָׁעָה גִּטּוֹ גֵּט. וַאֲפִלּוּ חָלִים בְּעָלְמָא, שֶׁאֵינוֹ שָׁפוּי לְגַמְרֵי וְעַיֵּן לְעֵיל סִימָן קי"ט סָעִיף ו':

One who is occasionally SICK (meaning, healthy, as in "and you have healed me and enlivened me" in Isaiah 38:16)), and occasionally foolish when SICK, he is considered sharp-sighted for all his words. And if under this condition he expels his wife, that expulsion is considered a valid divorce. Even if he is SICK unknowingly, and not completely sane. See above mark 119 verse 6.