Tosefta su Levitico 18:78

The precepts were given to Israel for no reason other than for Israel to stay alive, for it is said of the precept, "Which if a man do, he shall live by them" (Lev. 18:5) - live by them and not die by them. Therefore, when there is danger to life, no precept is to be insisted on except those prohibiting idolatry, unchastity, and murder. When does the rule apply? Not in a time of religious persecution. But during a time of religious persecution, a man must be willing to give up his life even for the least demanding of precepts, as it is said, "You shall not profane My Holy Name - I am to be hallowed among the children of Israel" (Lev. 22:32).

R. Aha said in the name of R. Akiva. Behold, it says: “If a thief is found tunneling in…” Is the house’s owner certain or uncertain? You must say he is uncertain. If they kill a person to save a life in a case of uncertainty, it is logical that they should push off the Sabbath, in order to save a life in a case of uncertainty. Behold, the commandments were only given to Israel that they might live by them, as it is written “Which a man shall perform and live by them” - he shall live by them, and not die by them. Nothing takes precedence over saving a life, save idolatry, sexual sins, and murder. In which circumstances are these things said? When it is not a time of persecution. But, when it is a time of persecution, even when it comes to the smallest of small commandments, a person should die for it, as it is written: “Do not profane my holy name” (Leviticus 22) and “the Lord made everything for his own sake” (Proverbs 16).