Yoreh Deah Siman 267 Seif 52

נב כְּשֵׁם שֶׁהָאִשָּׁה מְבִיאָה גִּטָּהּ וְאֵינָהּ צְרִיכָה לְקַיְּמוֹ, הוֹאִיל וְהַגֵּט יוֹצֵא מִתַּחַת יָדָהּ, כָּךְ הָעֶבֶד שֶׁשְּׁטָר שִׁחְרוּר יוֹצֵא מִתַּחַת יָדוֹ אֵינוֹ צָרִיךְ לְקַיְּמוֹ.

 

Seif 52

Just as when a woman brings a bill of divorce, she does not have to have the authenticity of the document verified, because the bill of divorce is in her possession so when a servant’s bill of release is in his possession, he does not have to have the authenticity of the document verified.