{Not a hair of your head shall perish} (	hrix ek t(8873)
kephal(8873) hum(936e) ou m(8820)apol(8874)ai). Only in Luke. Second aorist
middle subjunctive of apollumi with ou m(885c) (double negative).
Jesus has just said that some they will put to death. Hence it is
spiritual safety here promised such as Paul claimed about death
in  Php 1:21 .