Fat Of The Land Meaning

(idiomatic) The greatest part of anything; the finest and most abundant share of resources; the cream of the crop.

Example:   Under capitalism, the wealthy live off the fat of the land.
1611, Bible (KJV), Genesis 45:18:
  And take your father and your households, and come unto me: and I will give you the good of the land of Egypt, and ye shall eat the fat of the land.