# It came about that

This phrase is used here to mark an important event in the story: the start of the flood. If your language has a way for doing this, you could consider using it here.

# after the seven days

"after seven days" or "seven days later"

# the waters of the flood came upon the earth

The implicit information, "it started to rain" can be made explicit. Alternate translation: "it started to rain and the waters of the flood came upon the earth" (See: [[rc://en/ta/man/jit/figs-explicit]])