Halakhah zu Wajikra 18:5

The Talmudic maxim "to save one life is tantamount to saving a whole world" (Sanhedrin 37a) indicates that the value of human life is infinite. A fraction of infinity is still infinity. Nothing in this world is of higher value or greater ethical import than human life. Even Torah commandments of the Holy One, blessed be He, must give way to the higher value of preserving human life. The Biblical verse "You shall study and observe My laws and live thereby" (Lev. 18:5) is interpreted in the Talmud (Yoma 85b) to mean that the saving of a life takes precedence over Sabbath observance. By inference, all other Torah laws must also be suspended to save a life since none are more important than the Sabbath laws.

And all the sacrifices are all from all the laws are. Sages said, that for the work of sacrifice the world stands; That in the making of laws and judgments the righteous gain the life of the next world. And the Torah preceded a commandment on the laws, which is said (Leviticus 18: 5): "And ye have kept my statutes and my judgments, which if a man do, he shall even live in them":

In addition, Ramban, in his Commentary on the Bible, Leviticus 25:36, interprets the verse, "And your brother shall live with you," as constituting a general obligation to preserve the life of one's fellow. Earlier, R. Aḥa'i Ga'on, She'iltot, She'ilta 38, adduced the discussion found in the Gemara, Baba Mezi'a 62a, in interpreting this verse in a similar manner. R. Shimon ben Ẓemaḥ Duran, Teshuvot Tashbaz, III, no. 37, declares that the verse "And he shall live by them" (Leviticus 18:5) constitutes yet another mizvah commanding the preservation of life. The Gemara, Yoma 85b, renders this passage as meaning, "And he shall live through [the commandments] but he shall not die by means of them," and accordingly interprets this verse as establishing the principle that mizvot are suspended in face of life-threatening dangers. The regulation mandating suspension of mizvot in face of danger, argues Tashbaz, must be understood as establishing a general obligation to preserve life whether or not violation of biblical law is necessary to accomplish that goal.