Exodus 21:21 - Clarke's commentary and critical notes on the Bible

Notwithstanding, if he continue a day or two, he shall not be punished: for he is his money. If the slave who had been beaten by his master died under his hand, the master was punished with death - see Genesis 9:5, Genesis 9:6. But if he survived the beating a day or two the master was not punished, because it might be presumed that the man died through some other cause. And all penal laws should be construed as favourably as possible to the accused.