Yoreh Deah Siman 267 Seif 56

 

נו הַמּוֹסֵר גֵּט שִׁחְרוּר לְעֶבֶד עַל מְנַת שֶׁיִּשְׁתַּחְרֵר בְּבֵית דִּין, לֹא שְׁנָא אִם כָּתוּב בּוֹ: עַצְמְךָ וּנְכָסַי קְנוּיִים לְךָ, לֹא שְׁנָא אִם כָּתוּב בּוֹ: כָּל נְכָסַי קְנוּיִים לְךָ, עַצְמוֹ קָנָה עַל פִּי דִּבּוּרוֹ שֶׁיֹּאמַר: בְּפָנַי נִכְתַּב וּבְפָנַי נֶחְתַּם; נְכָסִים לֹא קָנָה עַד שֶׁיִּתְקַיֵּם בְּחוֹתְמָיו.

 

Seif 56

If one transfers a bill of release for a servant with the intention that he be released in a court, we  do not differentiate if it says: Yourself and the assets you purchased, we  do not differentiate if it says: all my property is acquired by you, he acquired his own person by saying: Before me it was written and signed; However he does not acquire it until the authenticity of the document is verified.