'Blood guiltiness' in the Bible

Now therefore, my lord, as Yahweh lives, and as your soul lives, since Yahweh has withheld you from blood guiltiness, and from avenging yourself with your own hand, now therefore let your enemies, and those who seek evil to my lord, be as Nabal.

Blessed is your discretion, and blessed are you, that have kept me this day from blood guiltiness, and from avenging myself with my own hand.