Deuteronomy 22:8
When thou buildest a new house, then thou shalt make a battlement for thy roof, that thou bring not blood upon thine house, if any man fall from thence. When thou buildest a new house, then thou shalt make a battlement for thy roof, that thou bring not blood upon thine house, if any man fall from thence.
When a new private house is built, a protective parapet wall or battlement must be placed around its roof so that no one falls from it and dies, otherwise blood or bloodguilt for that death comes upon the house and household. The householder is thereby made responsible for preventing the danger. Houses in Palestine generally had flat roofs that people used for walking, sleeping, and talking, including as sleeping places, so the parapet served the practical purpose of protecting those using the roof from falling and preventing accidents.
The instruction about building houses belongs to a system in which Israel's whole life, including work and daily practices, was to educate the people in holiness and point them to the Redeemer who takes away the sins of the world. The command was a building law given to Israel as a nation; as national law it is not binding today, though its underlying principle remains binding. The command teaches that building character requires safeguards like the roof wall: without them a person can cause another's ruin and fall, while a well-built character protects others and guides them safely. The safeguard of character means making straight paths so that those who are weak are not turned aside.
The battlement illustrates temperance for growing cities: sobriety and education are needed as a safeguard to protect society from the dangers of intemperance and poor government. Temperance is the protective barrier for the new house of civilization that keeps bloodguilt from a society that gives political power to the people by guarding against the harms caused by strong drink.