Reference for Gittin 1:6
הָאוֹמֵר, תֵּן גֵּט זֶה לְאִשְׁתִּי וּשְׁטָר שִׁחְרוּר זֶה לְעַבְדִּי, אִם רָצָה לַחֲזֹר בִּשְׁנֵיהֶן, יַחֲזֹר, דִּבְרֵי רַבִּי מֵאִיר. וַחֲכָמִים אוֹמְרִים, בְּגִטֵּי נָשִׁים, אֲבָל לֹא בְשִׁחְרוּרֵי עֲבָדִים, לְפִי שֶׁזָּכִין לָאָדָם שֶׁלֹּא בְּפָנָיו וְאֵין חָבִין לוֹ אֶלָּא בְּפָנָיו. שֶׁאִם יִרְצֶה שֶׁלֹּא לָזוּן אֶת עַבְדּוֹ, רַשַּׁאי. וְשֶׁלֹּא לָזוּן אֶת אִשְׁתּוֹ, אֵינוֹ רַשָּׁאי. אָמַר לָהֶם, וַהֲרֵי הוּא פוֹסֵל אֶת עַבְדּוֹ מִן הַתְּרוּמָה כְּשֵׁם שֶׁהוּא פוֹסֵל אֶת אִשְׁתּוֹ. אָמְרוּ לוֹ, מִפְּנֵי שֶׁהוּא קִנְיָנוֹ. הָאוֹמֵר, תְּנוּ גֵט זֶה לְאִשְׁתִּי, וּשְׁטָר שִׁחְרוּר זֶה לְעַבְדִּי, וּמֵת, לֹא יִתְּנוּ לְאַחַר מִיתָה. תְּנוּ מָנֶה לְאִישׁ פְּלוֹנִי, וּמֵת, יִתְּנוּ לְאַחַר מִיתָה:
If one says: Give this get to my wife, or this writ of manumission to my bondsman, if he wishes to retract with both, [before they reach the hand of the woman or of the bondsman], he may do so [and the messenger may not acquire the writ on their behalf; for it is a liability to them in that it deprives them of their sustenance.] These are the words of R. Meir. The sages say: [He may retract] with the gittin of women, but not with the manumissions of bondsmen. [And the halachah is in accordance with the sages.] For a man is accorded benefit even not in his presence, but liability is imposed upon him only in his presence. For if he wished not to feed his bondsman, he could do so, [so that when he frees him he does not cause him to lose his sustenance]; but he is not permitted not to feed his wife, [so that when he divorces her, he causes her to lose her sustenance.] He (R. Meir) said to them: But he disqualifies his bondsman from terumah, just as he disqualifies his wife! They answered: That is because he is his acquisition. [That is, the reason the bondsman of a Cohein eats terumah is that he is his acquisition — just as the beast of a Cohein eats terumah vetch, and there is no ascendancy in this. Therefore, if he frees him, even though he disqualifies him from eating terumah, this is no liability to the bondsman.] If one says: Give this get to my wife, or (give) this writ of manumission to my bondsman, and he died, they are not to be given after his death. [For it is not a get until it reaches her hand, and when it reaches her hand, he is dead; and there is no get after death. And with the writ of manumission, too, when it reaches his (the bondsman's) hand, he (the owner) is dead and has no authority over him.] (If one says:) Give a manah to this and this man, and he dies, it is to be given after his death [even if he did not say: "this manah," for the words of a shechiv mera (one at the point of death) are as "written and given"].