'Seventy seven' in the Bible

If Cain will be avenged seven times, truly Lamech seventy-seven times."

All the days of Lamech were seven hundred seventy-seven years, then he died.

He caught a young man of the men of Succoth, and inquired of him: and he described for him the princes of Succoth, and its elders, seventy-seven men.

The children of the captivity, who had come out of exile, offered burnt offerings to the God of Israel, twelve bulls for all Israel, ninety-six rams, seventy-seven lambs, and twelve male goats for a sin offering: all this was a burnt offering to Yahweh.