Why Moses Asked the Spies if the Land Had a Tree

"And what the land is, whether it be fat or lean" (Numbers 13:20). And what sign did he give them, that they might discern whether it is fat or whether it is lean? Thus he said to them: If you see that the land is clayey and flinty and rocky, it is lean; and if you see that it is manured and black, it is fat. "Whether there be a tree therein" — they asked whether Job was still alive or not, for he was in the land of Uz; and his years are long like a tree. For if he had died, know that no merit remained for them.