Lacking secure banking systems, many people buried their treasure to keep it safe. The labourer who finds the treasure hides it because it is part of the field, by law; because hiding it keeps it safe from thieves; and finally, because he is keeping the treasure secret.
At that time it was difficult to keep treasures, for secure banking systems did not yet exist and there were many thieves and robbers. Especially in times of war, many treasures were buried. The man who, by chance, probably while plowing, discovers the treasure, is a poor day labourer who works on another man’s field. The man hides the treasure again for three reasons: first, the treasure must remain part of the field, for according to Jewish civil law, one bought a field with everything in it, unless agreed otherwise. Second, the treasure must be secured against thieves. Third, he must keep it secret (Bette, page 315).
44 “The kingdom of heaven is like treasure hidden in a field, which a man found and covered up. Then in his joy he goes and sells all that he has and buys that field.