He does not allow you to kill your servant. He does not allow you to harm them. He does not allow your cattle to harm them. He does not allow your servant to work on the Sabbath. He does not allow you to kidnap and sell people into slavery. He does not allow you to buy slaves that were kidnapped. He does not even allow you to return a runaway slave. That means if a slave feels oppressed or mistreated, they can literally just walk out and nobody can stop them.

You cannot ignore these verses. To suggest you can kill your servant, so long as they die after two days, but no later and no sooner, is incoherent. You cannot exaggerate what is written.

Previously I pointed to the ambiguity of the verse, and how different translations render it differently. I will withdraw that argument until I receive word from a rabbi I asked about the translation. In the meantime I want to emphasize a key point that stands regardless of the proper translation. These verses are concerned with punishments. They are not discussing what is permissible, or what you're allowed to do. They are discussing the consequences of wrong behavior.

I find it interesting that the verses preceding the one in question bear many similarities:

“If men contend with each other, and one strikes the other with a stone or with his fist, and he does not die but is confined to his bed, if he rises again and walks about outside with his staff, then he who struck him shall be acquitted. He shall only pay for the loss of his time, and shall provide for him to be thoroughly healed."

These verses are telling you the punishment for hurting someone to the point he is bedridden for a few days. The punishment is money. You must pay them for their lost time. However, the question then becomes what happens if it's your servant? Again money. Except that in this case the servant himself was your income. Hurting your servant is like shooting yourself in the foot. The time they spend bedridden is your own loss of money. This is why translations rendered thus make more sense: "but they are not to be punished [with death] if the slave recovers after a day or two, since the slave is their money."

However, even if it is rendered the opposite way, "if he remains alive a day or two, he shall not be punished [with death]; for he is his property." It is still not condoning murder, it is not allowing it, it is not giving permission, endorsement, or support to it. It is telling you the punishment for it, which is monetary loss.

We can argue about whether or not the punishment is too light. I myself agree it does seem too light. But to argue the Bible approves of murdering of your slaves, is not substantiated by the verse. Killing your servant, killing anybody, is off limits