blood. Put by Figure of speech Metonymy (of the Subject), for the guilt of bloodshedding.
souls. Hebrew. nephesh. App-13.
poor. helpless. Hebrew. 'ebyon. See note on Proverbs 6:11.
it: i.e. the guilt (of bloodshedding) on the "poor innocents".
these: i.e. these [thy skirts] which evidence it. Note the Figure of speech Ellipsis, in this verse. Compare Jeremiah 22:17.