BT Šab 129a(53) :אי פגע בשיכבא ירקי אפיה‏ : if he encounters a dead body, his face will become pale
See the entire entry for yrq#2 vb. to be pale; to be green

BT Šab 129a(53) :ואי פגע במאן דיקטל נפשא מאית‏ : if he encounters one who has killed a living person he will die
See the entire entry for np̄eš, nap̄šā n.f. soul; life; self