"It symbolizes the future"- What is 'it'? Why is it considered as 'future'?

The expression is taken from famous story writer H.E. Bates' significant short story The Ox.

       Here 'it' refers to the hard-earned and hard-saved money of Mrs. Thurlow. This line serves to indicate the immense importance of her lost money to Mrs. Thurlow. The story-teller emphasizes here how she did look upon the loss of her money.

Mrs. Thurlow's saving had much significant to her. That did not mean simply a store of sovereigns, silver and coin to her. It actually stood for something much more significant in her life. She saved this money for the future of her two sons. Infact, it was the symbol of her optimism about their future success in life as some assistance in shops, clerks and even butlers. Their entire future actually was based on that very saving.

This line signifies the value of her saving to Mrs. Thurlow. The loss was not merely the loss of some money to her. It was a dreadful blow to her future - the future that she had built about her two sons.