Pikuach nefesh is Hebrew for “saving a life.” It comes from the rabbinical principle of pikkuah nefesh doheh Shabbat—“rescuing a life in danger takes precedence over the Sabbath.” The principle comes from a rabbinical interpretation of Leviticus 18:5, “Keep my decrees and laws, for the person who obeys them will live by them. I am the LORD.” The Babylonian Talmud points out that God says His people will “live by” the Law—as opposed to “dying by” it. Thus, the Law is designed to promote life, and the preservation of human life is a higher priority than the observance of the Law.
In the Law of Moses, God told Israel not to work on the Sabbath, and the penalty for working on the Sabbath was death (Numbers 15:32ff). However, pikuach nefesh says that, if someone’s life is in danger, then it is permissible to break the Sabbath by working to save that person’s life. For example, Jewish ambulance drivers may work and bear burdens on the Sabbath, and Jewish nurses may give medical attention to their patients on the Sabbath. Pikuach nefesh implies more than permission to violate the Law, however; it demands its violation when there is a life at stake. In matters of life and death, it is incumbent upon us to act, even when that action violates the letter of the Law.
Jesus followed the principle of pikuach nefesh when He healed people on the Sabbath (Luke 13:10–13). When a synagogue leader objected, Jesus defended His actions with this challenge: “Doesn’t each of you on the Sabbath untie your ox or donkey from the stall and lead it out to give it water?” (Luke 13:15). If one may violate the Sabbath for the sake of animals, how much more for the sake of human beings, created in the image of God? As Jesus pointed out, the Sabbath was made for man, not man for the Sabbath (Mark 2:27).
Of course, believers in Jesus are no longer required to keep the Sabbath. We are under a new law—the Law of Christ, in which we “carry each other’s burdens” (Galatians 6:2; see also Colossians 2:16). Since Christians are not bound by the Mosaic Law, the rule of pikuach nefesh is not really applicable to them. However, under the Old Covenant, Jesus gave pikuach nefesh His stamp of approval as a principle that reflected God’s mercy and compassion.