What do you suppose Lennie's statement might suggest allegorically when he says, "...live on the fatta the lan'...an' rabbits," especially in light of the way george goes on to describe it?

To live off of the fat of the land implies that the land will offer people whatever they need to survive........ allegorically similar to Jesus feeding the 5,000 and the Lord providing. Numerous Biblical stories could run parallel here, this was the first that came to mind.