Their feet. They. Feet being put by Figure of speech Synecdoche (of Part), for the whole person. Quoted in Romans 3:15; Romans 3:16.
evil. Hebrew. ra'a'. App-44.
innocent blood. Reference to Pentateuch. Only here in Isaiah; five times in Deuteronomy (Isaiah 19:10; Isaiah 19:13; Isaiah 19:21; Isaiah 19:8; Isaiah 19:9).
paths. highways. See note on Isaiah 7:3.