This word is used here to mark a new part of the story.
a famine happened
"there was a famine" or "there was another famine"
in the land
You can state explicitly the land to which this refers. AT: "in the land where Isaac and his family lived" (See: rc://en/ta/man/translate/figs-explicit)
that had been in the days of Abraham
"that had happened during Abraham's life" or "that had happened while Abraham was alive"