It is interesting to note that while Cain turns to God in the second singular person, God responds him talking to him in the third person. God doesn’t say whoever kills you … but whosoever slayeth Cain. In so doing, Cain becomes the figure of every man who – because of what he has done – is forced to live with a great remorse of conscience and above all with the fear of revenge .
God’s response seems to be marked by violence, certainly not compatible with the intent to protect Cain. Yet the sevenfold revenge means exactly this. With these words, God wants to restrain the rapid escalation of humanity towards a future full of violence. The words represent a brutal deterrent for a brutal humanity, when violence degenerates. Seven is a numeric symbol that indicates totality, so who will touch Cain will have an exemplary punishment. By whom? Not by God, because he says whosoever slayeth Cain. There is a message to be read between the lines and about humanity, every single man. If Cain killed his brother, whoever kills cannot avenge the death of Abel, since the only effect will be the increase in violence. A kind of left-hand prophecy that announces what will happen in the following chapters, which tell the human story before the flood.
God set a mark upon Cain – the famous Mark of Cain – which is commonly understood as a sort of mark of the murderer, of anyone committing any kind of violence against his brother. Instead, it is a sign of protection, perhaps a tattoo, as some suggest. It is the extreme attempt to stop the chain of violence, a revenge triggered by what Cain did. The sign is something that acts as a deterrent against the intention to kill. It will be helpful?