The American English word “slave” refers to a person whom the owner can legally kill, rape, torture or mutilate, was kidnapped into slavery (no other way) and if freed, never has meaningful rights, and whose status as such is a totally a function of skin color. The is no word in Hebrew for slavery. Those who believe there is are showing their ignorance of the Hebrew language. Unfortunately, many frei Jews (and almost all Christians) have no knowledge of Taanach other than from dubious translations.
SLAVERY as defined in English is totally prohibited in Tanach and under Jewish law would be considered a crime.
A better translation of the Hebrew word ??? is servant.