What IS good, and how do we determine it?

[Brakeman]

https://en.wikipedia.org/wiki/Voluntary_slavery

[b]Voluntary slavery (or self-sale) is the condition of slavery entered into at a point of voluntary consent. ..

Once again, you guys apply your modern day ideals to ancient civilizations. It was common practice for people to sell themselves into slavery if they were impoverished or owed a debt they didn't have the means to pay... what solution would you offer? Especially in a society that was based on the bartering system, seeing how the Hebrews just came out of slavery under the Egyptians.

If a homeless person agreed to work for me in exchange of food and shelter, it's your position that it's immoral?

Very dishonestly you left off the explanation portion of the wiki article that explains why the term is non-sense.

Modern Analysis

Jean-Jacques Rousseau contends that in a contract of self-enslavement, there is no mutuality. The slave loses all. The contract negates his interests and his rights. It is entirely to his disadvantage. Since the slave loses his status as a moral agent once the slave contract is enforced, the slave cannot act to enforce anything owed to him by his master. Rousseau contrasted this to the social contract, in that the subjects of the government have control over their masters.[5] John Stuart Mill wrote a critique of voluntary slavery as a criticism of paternalism.[6]

This means that slavery is not a form of "payment" as indentured servitude because the slave losses all rights to self determination and cannot enforce his part of the bargain or contract. In indentured servitude a man had rights of redress in which he was only endeared to work off and suffer an amount that was owed, whereas slavery is a total loss of identity to a master. An indentured servant owed a limited value, not his lifetime and being.

If you gave a meal worth 10 dollars to a homeless person, you could expect 10 dollars worth of respectable work if he was in agreement as a form of indentured servatude. What he could not and would not consent to is to be your slave in which you could toy with his dignity as a cat does with a ball, take any thing and everything from him forever without regards to its equivalence to your initial payment. You could not beat him and refuse to allow him to ever retreat from his bondage until you and only you felt like it.

No, the modern world sees the evil in that and huge numbers of soldiers fought and died to wipe that horrible practice from the earth, We will not allow you to enslave a homeless person just because you baited him with food.