Exodus 21:20–21 mandates punishment of slave owners who beat their slave.
And if a man beats his male or female servant with a rod, so that he dies under his hand, he shall surely be punished.
Actually, he (slave owner) only gets punished if they die right then and there. If they linger from their beating and die a few days later, no offense has been done at all, in the eyes of God.
How is it that you can cite the source and yet not actually read it? From your citation, Exodus 21:20-21, the slave owner is not to be punished for beating their slave unless the slave dies from the beating fairly soon after the beating. If the slave recovers from the beating the slave owner is "not to be punished".
Exodus 21:20-21
20 “Anyone who beats their male or female slave with a rod must be punished if the slave dies as a direct result,
21 but they are not to be punished if the slave recovers after a day or two, since the slave is their property.
This is a point on which
different Bible translations disagree with one another. What skepticalbip quoted was the New International Version; ideologyhunter read a different version. Below I've quoted some sample translations; there are many more at the website. Here's the Complete Jewish Bible:
"21 except that if the slave lives for a day or two, he is not to be punished, since the slave is his property."
King James Version:
"21 Notwithstanding, if he continue a day or two, he shall not be punished: for he is his money."
The Living Bible:
"21 However, if the slave does not die for a couple of days, then the man shall not be punished—for the slave is his property."
Revised Standard Version Catholic Edition:
"21 But if the slave survives a day or two, he is not to be punished; for the slave is his money."
World English Bible:
"21 Notwithstanding, if his servant gets up after a day or two, he shall not be punished, for the servant is his property."
The Wycliffe Bible:
"21 Soothly if the servant liveth over this beating one day, or twain, the smiter shall not be subject to the pain of death, for the servant is his master’s chattel."
Young's Literal Translation:
"21 only if he remain a day, or two days, he is not avenged, for he [is] his money."
Also, for what it's worth, here's how Martin Luther translated it:
"21 Bleibt er aber einen oder zwei Tage am Leben, so soll er darum nicht gestraft werden; denn es ist sein Geld."
which my sketchy German and Google Translate agree means:
"21 But if he lives a day or two, he shall not be punished for it; because it's his money."
So different translators evidently read the same Hebrew* and some of them thought it meant the slave recovers after one or two days and others thought it meant the slave dies after one or two days. On the one hand, the older translations saying the slave dies are less informed by modern philological scholarship; on the other hand, their linguistic objectivity can't have been contaminated by modern antislavery sentiment. So it's not clear whether God himself instructs us in the excusable way to beat your slaves to death.
One thing that puzzles me about Christian fundamentalists -- people who believe that the Bible is the literal Word of God and that living according to God's directions is literally the most important thing there is for a Christian to do -- is how very, very few of them have taken the trouble to read God's Word for themselves, and learn Hebrew.
(* Moreover, some translators didn't work directly from Hebrew but retranslated from St. Jerome's translation into Latin. "21 Sin autem uno die vel duobus supervixerit, non subjacebit poenae, quia pecunia illius est." Good luck to any classicists...)