This precept also has reference to the preservation of human life. We know that the roofs of the Jewish houses were fiat, so that they might freely walk upon them. If there were no railings round them, a fall would have been fatal; and every house would have often been a house of mourning. God, therefore, commands the edge to be fortified with battlements, or railings, or other inclosure, and accompanies the injunction with a severe denunciation; for He declares that the houses would be defiled with blood, if any one should fall from an uninclosed roof. Now, if guile were thus contracted by mere incautiousness, it hence appears how greatly He abominates deliberate cruelty; and, if it behooved everybody to be thus solicitous as to the lives of their brethren, it shows how criminal it is to injure them purposely and in enmity.