Halakhah for Yoma 170:1
אבל להחיות אפילו מעל מזבחי ומה זה שספק יש ממש בדבריו ספק אין ממש בדבריו ועבודה דוחה שבת קל וחומר לפקוח נפש שדוחה את השבת נענה רבי אלעזר ואמר ומה מילה שהיא אחד ממאתים וארבעים ושמונה איברים שבאדם דוחה את השבת קל וחומר לכל גופו שדוחה את השבת
but to save life<span class="x" onmousemove="('comment',' If one had been sentenced to death, there is ample provision for a revision, if even at the last moment someone claims to have found evidence of the accused's innocence. If a priest has such evidence, or is only believed to have it, he would be taken down from the altar even after he had commenced, and before having completed, his service.');"><sup>1</sup></span> one may take one down even from the altar. Now if in the case of this one, where it is doubtful whether there is any substance in his words or not, yet [he interrupts] the service in the Temple [which is important enough to] suspend the Sabbath, how much more should the saving of human life suspend the Sabbath laws! R'Eleazar answered and said: If circumcision, which attaches to one only of the two hundred and forty-eight members of the human body, suspends the Sabbath,<span class="x" onmousemove="('comment',' The circumcision must take place on the eighth day, even if that day falls on the Sabbath, suspending the law of the Sabbath, which prohibits operation, as well as preparations leading to it.');"><sup>2</sup></span>