Exodus Twenty-One - Serving Time

"Now these are the judgments which you shall set before them: If you buy a Hebrew servant, he shall serve six years; and in the seventh he shall go out free and pay nothing. If he comes in by himself, he shall go out by himself; if he comes in married, then his wife shall go out with him," Exodus 21:1-3, NKJV. #ServingTime

While the word 'slave' is only directly translated once from the original Greek and Hebrew into English in the scriptures, the more common term used is 'servant'; God established the master-servant, or in our day, employer-employee relationship on the earth as an example of the very important spiritual principle of working as unto the Lord.
Genesis 9:25-29, Job 7:1-3 and John 13:12-17.