What lines do Beowulf reference the flood?

Lines 1650-1887

The story recounted on the hilt of the sword is that of Noah's Great Flood as recorded in Genesis. This reinforces the constant emphasis on water that has been shown throughout the poem. The Flood narrative has a special relevance here. We are reminded of the fate of all Cain's previous descendants in that great flood; again his descendants (Grendel and Grendel's mother) have met the same fate by dying in a watery grave. However, this curses the waters for men‹from this point, man's travel by water will be doomed, leading to war and death.