[xzins]

Notwithstanding, if he gets up after a day or two, he shall not be punished, for he is his property.

You didn't read it fine. The HNV clarifies the literal translation. (only if he remain a day, or two days, he is not avenged, for he [is] his money.)

If after the beating the slave remains (continues/survives) there is to be no vengeance.

[js1138]

So what part of this do you think is a good moral lesson?