John Wesley on Exodus 21:20

Direction is given what should be done, if a servant died by his master's correction. This servant must not be an Israelite, but a Gentile slave, as the Negroes to our planters; and it is supposed that he smite him with a rod, and not with any thing that was likely to give a mortal wound, yet if he died under his hand, he should be punished for his cruelty, at the discretion of the judges, upon consideration of circumstances.