The second tablet of the ten commandments begins with two stark, simple words: Lo Tirtzach, do not murder. Closely entwined with the Torah's impassioned insistence on the sanctity of human life, the prohibition on shedding innocent blood lies at the very heart of Judaism's theology and social vision. Parashat Mas'ei reiterates this insistence, and adds a crucial coda: not taking a ransom for the life of a murderer. The point is that one may never place a monetary value on a human life. To shed innocent blood is to commit a morally and theologically unimaginable crime. This is the value that biblical law expresses and enforces, that we are called to uphold today, in order that the land itself is not polluted by the blood of innocents.