A battlement for thy roof - Houses in the East are in general built with flat roofs, and on them men walk to enjoy the fresh air, converse together, sleep, etc.; it was therefore necessary to have a sort of battlement or balustrade to prevent persons from falling off. If a man neglected to make a sufficient defense against such accidents, and the death of another was occasioned by it, the owner of the house must be considered in the light of a murderer.
These precepts are designed to cultivate a spirit of humanity. Compare Deuteronomy 25:4; Leviticus 22:28; and 1 Corinthians 9:9-10.
Deuteronomy 22:8
The roofs of houses in Palestine were flat and used for various purposes. Compare Joshua 2:6; 2 Samuel 11:2; Acts 10:9, etc. A battlement was almost a necessary protection. It was to be, according to the rabbis, at least two cubits high (about 3 ft.).