Explain how financial management is based on the saying "A bird in hand worth two in the bush"?

Planning is the future of future is in present. Once you have resources (for e.g cash in hand or bank rather receivable) you may have couple of ways to use it. therefore it say that A bird .....

Future is uncertain and risky.

Pre-thinking is  very essential before taking Risky Investments Deceisions.  Ours is better when some uncertainities remain with our future  course of action and  without proper  study of all risk factors and from different angles we should not proceed with.