This parable was told only to Christ's close disciples and not the crowd. The Kingdom of Heaven is like the treasure a man discovered in a field. In ancient times, although there were bankers, the custom was to bury valuables, such as gems and money, to keep them safe from thieves or enemies. People believed this to be the better safeguard rather than to hand their possessions to a banker.
Treasure symbolises that which is of remarkable value.
To obtain the treasure meant the land must be also obtained, for if any treasure was found it belonged to the owner, and not the finder. The Treasure is the Kingdom of God. The Treasure of The Kingdom of God is among the world. God's treasure amongst the world is known only by God and is made up of His people, those who have found the value of His Kingdom. The Kingdom of Heaven is the most valuable possession any one can have, those who truly enter the Kingdom know of its value.