Genesis 5:7 says,
“After he begot Enosh, Seth lived eight hundred and seven years, and had sons and daughters.”
Genesis 5:12 states,
“Cainan lived seventy years, and begot Mahalalel.”
Genesis 5:26 adds,
“After he begot Lamech, Methuselah lived seven hundred and eighty-two years, and had sons and daughters.”
In those passages, we could simply argue there is nothing special about, “seven,” for it is simply part of a man’s age. Genesis 5:31 says that Lamech, the father of Noah lived,
“So all the days of Lamech were seven hundred and seventy-seven years; and he died.”
That may also be coincidental. Lamech though was a spiritual man, for he said of his son Noah,
“And he called his name Noah, saying, ‘This one will comfort us concerning our work and the toil of our hands, because of the ground which the LORD has cursed'” (Genesis 5:29).
Was there a connection between Lamech’s age and his prophecy about his son, or is this making more out of the text than the Holy Spirit intended?
What do you think? Remember we want to speaks as the Bible speaks, not more and not less!
Sevens in the Bible 
Lamech’s lifespan was a pretty number, but he may not have thought so: he died before his father, and younger than all his ancestors who lived out their natural lives.
Noah became a sign of Christ, in that he was a saviour of the world, and no-one was saved unless they were in him. However, Lamech’s prophecy was not fulfilled in Noah; after the flood, the human heart was not changed; we still toil and rebel. Nevertheless God promised by himself to hold back his anger from that time on. (Gen 8:21) It’s only in Christ that God’s wrath is satisfied, and in Christ that we are set free from the curse.
Thanks, Neville!