GEN623 It is axiomatic, according to Halakhah, that death coincides with cessation of respiration. The primary source of this definition is to be found in Yoma 85a in connection with suspension of Sabbath regulations for the sake of the preservation of human life. The case in point concerns an individual trapped under a fallen building. Since desecration of the Sabbath is mandated even on the mere chance that a human life may be preserved, the debris of a collapsed building must be cleared away even if it is doubtful that the person under the rubble is still alive. However, once it has been determined with certainty that the person has expired, no further violation of the Sabbath regulations may be sanctioned. The question which then arises is how much of the body must be uncovered in order to ascertain conclusively that death has in fact occurred? … the absence of respiration is regarded by all as being conclusive. … The necessity for the examination of the nostrils is based upon the assumption that it is possible for life to exist even though such life may be undetectable by means of an examination for the presence of a heartbeat … In demonstration of the principle that respiration is the determining factor, the Gemara cites [this verse].  [See also Genesis 2:7