1SA 19:5

5 For he did put his nefesh in his yad, and slaughtered the Pelishti [(Philistine)], and Hashem wrought Teshuah Gedolah for kol Yisroel; thou sawest it, and didst rejoice with simcha. Why then wilt thou commit chet against dahm naki [(innocent blood)], to slay Dovid chinom [(without cause)]?