Federal "Grants" For Emergency Services

So let me understand this. The federal government is "granting" millions of dollars to hundreds of different fire departments all across the country--places like Bridgeport Connecticut, Kansas City Missouri, Rochester New York, Seattle Washington, Los Angeles California... on and on and on. Hundreds of cities, large and small, rich and poor, from sea to shining sea.

But where did all that money come from?

From the taxes paid by, well, the people who live in... places like Bridgeport Connecticut, Kansas City Missouri, Rochester New York, Seattle Washington, Los Angeles California... on and on and on. They pay taxes to the federal government, where it gets filtered through the hands of bureaucrats, who then send (part of) the money back to the very places that it came from. Round and round it goes.

What exactly is the point of this? Where in here does it say the federal government should pay for local fire departments? Don't tell me the "general welfare" clause. If the Constitution can mean anything, it means nothing.