Yoreh Deah Siman 267 Seif 21

כא הַקּוֹטֵעַ יַד עֶבֶד כְּנַעֲנִי שֶׁל חֲבֵרוֹ, נוֹתֵן חֲמִשָּׁה דְּבָרִים לָאָדוֹן וְהָעֶבֶד נִזּוֹן מֵהַצְדָּקָה, אַף עַל פִּי שֶׁהָאָדוֹן לוֹקֵחַ הַשֶּׁבֶת, שֶׁהֲרֵי יָכוֹל לוֹמַר לוֹ: עֲשֵׂה עִמִּי, וְאֵינִי זָנְךָ. וְהָרִפּוּי, נוֹתֵן לִרְפוּאָתוֹ. וְאִם אֲמָדוּהוּ לְהִתְרַפְּאוֹת בְּה’ יָמִים, וְעָשׂוּ לוֹ סַמִּים חֲזָקִים שֶׁמִּהֵר לְהִתְרַפְּאוֹת בְּג’ יָמִים, הָאָדוֹן לוֹקֵחַ הַיִּתְרוֹן אַף עַל פִּי שֶׁהָעֶבֶד נִצְטַעֵר בַּסַמִּים הַחֲזָקִים.

Seif 21

If one amputates the hand of his neighbors  canaanite slave, he must give his master 5 things and to the slave he rightfully sustains him, although the master gets paid for his damages, you can say to him (the slave):work for me and I’ll sustain you. Although you must allow him to recover if he estimates his recuperation will take 5 days, and if you make him a tonic for strength and he quickly recuperates in 3 days, then the master can take and profit in spite of his slaves anguish (bec of the tonic).