The Mekhilta now draws the ultimate conclusion from the legal hierarchy it has been constructing. Murder overrides the sacrificial service. This is established. But saving a life overrides even the Sabbath. The Mekhilta uses these two established principles to derive a new one through a kal va-chomer, an argument from the lesser to the greater.
If the Sabbath, which is not overridden by murder (a convicted killer is not executed on the Sabbath), is nevertheless overridden by the saving of a life (pikuach nefesh (the vital soul)), then the sacrificial service, which is overridden by murder, must certainly be overridden by the saving of a life as well. The logic is airtight. If the stronger obligation (the Sabbath) yields to life-saving, then the weaker obligation (the Temple service) must yield even more readily.
This passage establishes one of the most important principles in all of Jewish law: the saving of a human life takes precedence over virtually every other commandment. The Mekhilta arrives at this conclusion not through a single dramatic declaration but through methodical legal reasoning, building the principle step by step from the relationships between Sabbath observance, Temple service, and capital punishment.
The hierarchy that emerges is clear. Saving a life stands at the very top. It overrides the Sabbath. It overrides the Temple service. It overrides everything except the three cardinal sins (idolatry, murder, and sexual immorality). The Mekhilta's chain of reasoning demonstrates that this principle is not a modern innovation or a sentimental preference. It is embedded in the structure of the Torah's own legal system, derivable from the relationships between its commandments through rigorous logical analysis.