Ephesians 6:9

You slave-owners, too, must maintain the same attitude toward your slaves, and stop threatening them, for you know that their real Lord and yours is in heaven, and that He never shows partiality.

Colossians 4:1

Masters, you must practice doing the right and square things by your slaves, for you know that you have a Master in heaven.

Treasury of Scripture Knowledge

Summary

If I did despise the cause of my manservant or of my maidservant, when they contended with me;

Bible References

The cause

Ephesians 6:9
You slave-owners, too, must maintain the same attitude toward your slaves, and stop threatening them, for you know that their real Lord and yours is in heaven, and that He never shows partiality.
Colossians 4:1
Masters, you must practice doing the right and square things by your slaves, for you know that you have a Master in heaven.