Leviticus 25:44-46New International Version (NIV)
44 “‘Your male and female slaves are to come from the nations around you; from them you may buy slaves. 45 You may also buy some of the temporary residents living among you and members of their clans born in your country, and they will become your property. 46 You can bequeath them to your children as inherited property and can make them slaves for life, but you must not rule over your fellow Israelites ruthlessly.
Exodus 21:2-4English Standard Version (ESV)
2 When you buy a Hebrew slave,[a] he shall serve six years, and in the seventh he shall go out free, for nothing. 3 If he comes in single, he shall go out single; if he comes in married, then his wife shall go out with him. 4 If his master gives him a wife and she bears him sons or daughters, the wife and her children shall be her master’s, and he shall go out alone.

Exodus 21:20-21New International Version (NIV)
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 d

1. Day or two, since the slave is their property.