The wisdom of prisoners

A young American 19-year-old was jailed on charges of terrorism was able to enter the US intelligence building and steal a lot of secrets and was nicknamed Fox, for cunning.
His father, an old man living alone desired to sow potatoes inside his farm, but he can not because his age he sent to his son jailed message telling him where:
My beloved Son, I wished to be with me now and help me in plowing the farm in order to sow potatoes I have no help me ..!
After a while, the father received a letter from his son telling him imprisoned in which:
I beg my father Aziz Never plowed farm where I hid something important when they get out of prison I'll tell you what it is!
I did not spend an hour on the letter And as men of intelligence and army besieging the farm and dig the ground Shubra Shubra not Ajdo Xia Gadro farm.
The letter arrived to the Father of his son the next day he says he has had:
Abe Aziz I hope that the land has been plowed well this is what I could do and I help you if you need Shi told me last