Job 31:13

“If I have despised the claim of my male or female slaves
When they filed a complaint against me,

Exodus 21:20-21

“If a man strikes his male or female slave with a rod and he dies at his hand, he shall be punished.

Exodus 21:26-27

“If a man strikes the eye of his male or female slave, and destroys it, he shall let him go free on account of his eye.

Leviticus 25:43

You shall not rule over him with severity, but are to revere your God.

Leviticus 25:46

You may even bequeath them to your sons after you, to receive as a possession; you can use them as permanent slaves. But in respect to your countrymen, the sons of Israel, you shall not rule with severity over one another.

Deuteronomy 15:12-15

If your kinsman, a Hebrew man or woman, is sold to you, then he shall serve you six years, but in the seventh year you shall set him free.

Deuteronomy 24:14-15

You shall not oppress a hired servant who is poor and needy, whether he is one of your countrymen or one of your aliens who is in your land in your towns.

Jeremiah 34:14-17

At the end of seven years each of you shall set free his Hebrew brother who has been sold to you and has served you six years, you shall send him out free from you; but your forefathers did not obey Me or incline their ear to Me.

Ephesians 6:9

And masters, do the same things to them, and give up threatening, knowing that both their Master and yours is in heaven, and there is no partiality with Him.

Colossians 4:1

Masters, grant to your slaves justice and fairness, knowing that you too 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

Exodus 21:20
“If a man strikes his male or female slave with a rod and he dies at his hand, he shall be punished.
Leviticus 25:43
You shall not rule over him with severity, but are to revere your God.
Deuteronomy 15:12
If your kinsman, a Hebrew man or woman, is sold to you, then he shall serve you six years, but in the seventh year you shall set him free.
Jeremiah 34:14
At the end of seven years each of you shall set free his Hebrew brother who has been sold to you and has served you six years, you shall send him out free from you; but your forefathers did not obey Me or incline their ear to Me.
Ephesians 6:9
And masters, do the same things to them, and give up threatening, knowing that both their Master and yours is in heaven, and there is no partiality with Him.
Colossians 4:1
Masters, grant to your slaves justice and fairness, knowing that you too have a Master in heaven.

General references

Exodus 21:26
“If a man strikes the eye of his male or female slave, and destroys it, he shall let him go free on account of his eye.
Exodus 23:6
You shall not pervert the justice due to your needy brother in his dispute.
Deuteronomy 24:14
You shall not oppress a hired servant who is poor and needy, whether he is one of your countrymen or one of your aliens who is in your land in your towns.