This is repeating a very early Divine principle: "Whoso sheddeth man's blood (purposefully), by man shall his blood be shed: for in the image of God made he man" (Gen. 9:6).
Hili ni jambo la Mungu la awali kabisa linalorudia "Atakayemwaga damu ya mwanadamu (kwa kusudi), damu yake huyo itamwagwa na mwanadamu: maana kwa mfano wake Mungu alimfanya mwanadamu" (Mwanzo 9:6).