Here "blood" is a metonym that implies "shed blood" and is associated with death. Here "your head" is a synecdoche referring to the man and means that he is responsible. Alternate translation: "You are responsible for your own death" or "You have caused your own death" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-synecdoche]])
Here "your own mouth" refers to the man himself. Alternate translation: "you have testified against yourself" (See: [[rc://en/ta/man/jit/figs-synecdoche]])