Hebrew slave is the reason or if you wish, common sense that serves the mind (the owner) in accomplishing the works of virtue (the number six) as if ordering and maintaining his house (soul). Before the soul is established in virtue, reason (along with the mind) is subject to whatever passion(s) (lust, anger, greed, ignorance, atheism…) one is enslaved to. Once moral perfection is achieved, reaching the seventh year as it were, then one is set free from all addictions (scripture also calls these the will of the flesh) and can freely and unerringly occupy himself with other spiritual contemplations.
Male slave is anger and female slave is desire. If one willfully, that is what the rod implies, gives into (strikes) his anger or lust and commits (hand) a sin (death) he shall be avenged, i.e. God will require of him to repent or suffer the consequences. If the slave survives, means the sin was committed unwillingly, accidentally or perhaps out of human weakness, then he can be forgiven without repercussions. Anger is useful (money) to the mind in fighting off temptations and desire in striving after what is good and holy.
Indeed :)