the farmer's treasure

there was a farmer when he being on the point of the death , he would their sons gives attention to his farm as he himself had given to it so he called them to his beside and said " My sons there is a great treasure hid on one of my vineyards " ,after his death their sons decided to find that treasure so they take their spades and mattock and dug over every portion of the vineyards could the treasure be in there but unfortunately they fond no treasure but fortunately the labor repaid their efforts ..I hope someone can correct me .

(There was a farmer who was dying. He summoned his sons so that giving them some advices. He told them to sit beside him and said:" There is a great Treasure hidden in my vineyard." After his death, his sons decided to find the treasure. So they took their spades and mattock and hugged every portion of the vineyards with the purpose of finding the hidden treasure. Unfortunately they found nothing but fortunately the labor repaid their efforts.)
I heared this story.