You are a fool is you don't believe that the president of the United States doesn't have money to spend at his discretion.
Any money that he has to spend was given to him through specific legislation appropriating those funds for specific purposes. The legislation had to pass Congress. Sure, maybe Congress appropriated funds for a "discretionary" account to be used in aiding foreign victims of natural disasters. Congress has only certain powers authorized to it and must operate within the scope provided by the Constitution. Show me the portion of the Constitution which authorizes Congress to appropriate funds to give to the President for such "discretionary" uses. Neither the Congress nor the President can do whatever they want. They are limited by the Constitution. Just because Congress appropriates funds and gives them to the President doesn't mean he can do whatever he wants with those funds.
Maybe this massive tragedy isn't the best situation upon which to make this point. There are a heck of a lot of other things that the President and the Congress does which are not authorized by the Constitution. However, the truth remains that most Federal expenditures to aid the victims of this tragedy are not within the bounds of the Constitution.
The fool is not the one who points out that the Constitution does not authorize a thing. The fool is the one who insists that it does but fails to back up their argument by providing the portion of the Constitution which proves it.