Sforno on Deuteronomy 5:14/ספורנו על דברים ה׳:י״ד

1למעו ינוח עבדך ואמתך כמוך, from the positioning of the commandment that your beasts of burden have to refrain from performing work for you on the Sabbath, before mentioning your children and servants observing such Sabbath rest, it is clear that the reasons animals owned by you must rest o the Sabbath is for the sake of the men working them, not because animals per se are subject to the spiritual concepts governing the Sabbath and its laws. The need for one’s slaves to observe the Sabbath rest is, of course, part of the reminder that when you were slaves you did not enjoy such a day of rest. Hence, do not treat your slave in the hateful you were treated when you were in his shoes.