Seventy Times Seven

If someone who kills Cain is punished seven times, then the one who kills me will be punished seventy-seven times!” [Genesis 4.24]

I guess for all the times I have read the Old Testament, and this story in particular, I never realized the similarity between this statement by Lamech (descendant of Cain) and the statement made by Jesus to Peter in the New Testament:

Then Peter came to him and asked, “Lord, how often should I forgive someone who sins against me? Seven times?” “No, not seven times,” Jesus replied, “but seventy times seven! [Matthew 18.21-22]

I cannot help but believe the conversation between Peter and Jesus had some reference to the incident with Cain and then Lamech. However, the circumstances are a bit different - quite a bit different.

It was the LORD who told Cain that anyone who killed him (Cain) would be dealt a seven-fold punishment. Note: It would seem God's punishment upon anyone who killed Cain was not actual death (because one can only die once - not seven times). 

It was as if God was saying, "My punishment upon you [Cain] is sufficient, so anyone else who tries to retaliate for Abel's murder will have to deal with Me - and it will be seven times worse!"

But why did Lamech (several generations after Cain) get the idea that anyone who killed him (since he had killed a young man), would be seventy-seven times worse (and not just seven)? Was it because the young man he killed first attacked Lamech? Was it because Lamech was only defending himself?

Is there a lesson here? Is there some principle by which to live?

I think I should be careful here. I am tempted to "Google" for an answer, but then, any answer found there might very well be as diverse as Google. I am looking for direction from the Holy Spirit about the (if any) relationship between these two instances that sound related.

Perhaps Lamech felt justified in defending himself. So, if God would retaliate seven times on someone who killed a purposefully and willfully guilty man (Cain), how much more would He retaliate the death of one only defending himself ? Seventy-seven times?

If Peter is asking Jesus how many times he should forgive, it could make sense that seven times would be a good number because of God's sevenfold protection of guilty Cain.

Bear with me... But, Jesus' reply to Peter could be seen more like Lamech's determination of  his own innocence (he killed in self-defense) and therefore God's protection would be much much more.

It would be then, in Lamech's confidence in his innocence, that we find Jesus' forgiving declaration of innocence upon our offenders. In other words, we are to see people as Jesus sees people (because of His redemption) - as innocent. To forgive seven times would imply we believe they are still guilty. But to forgive someone seventy-seven times (or seventy times seven, depending on accuracy of translation), would imply we believe they are (in the eyes of God because of Jesus) innocent.

Hmm.

Father, I believe You are still speaking to me about forgiveness. Please don't stop.