“Be careful not to practice your righteousness in front of people, to be seen by them. Otherwise, you will have no reward from your Father in heaven. 2 So whenever you give to the poor, don’t sound a trumpet before you, as the hypocrites do in the synagogues and on the streets, to be applauded by people. I assure you: They’ve got their reward! 3 But when you give to the poor, don’t let your left hand know what your right hand is doing, 4 so that your giving may be in secret. And your Father who sees in secret will reward you. ~ Matthew 6:1-4 (HCSB)

Harry Potter:

One thing there is a lot of in Potter is generosity. However, not all generosity is the same. The Malfoy’s could be labeled as very generous with their money, but they give to people and organizations that will give them a leg up. Lucius gives to Minister Fudge to gain power and influence over how the ministry is run. He donates his time as a member of the Hogwarts’ board in order to thwart and attempt to control Dumbledore — poor fellow never quite comprehends that Dumbledore will not be thwarted.

However, there is another kind of generosity more widely displayed in the series. A pure and innocent and true type. Here are three examples, though there are many more instances.

1. Dumbledore’s generosity to his students, not just financially but in another way Hagrid describes…

“Dumbledore was the one who stuck up for me after Dad went. Got me the gamekeeper job … trusts people, he does. Gives ’em second chances … tha’s what sets him apar’ from other Heads, see. He’ll accept anyone at Hogwarts, s’long as they’ve got the talent. Knows people can turn out okay even their families weren’ … well … all tha’ respectable. But some don’ understand that.” ~ Hagrid, Goblet of Fire, p. 455

2. Harry’s generosity to Fred & George Weasley…

“Harry,” said George weakly, weighing the money bag in his hands, “there’s got to be a thousand Galleons in here.”

“Yeah,” said Harry, grinning. “Think how many Canary Creams that is.”

The Twins stared at him.

“Just don’t tell your mum where you got it…although she might not be so keen for you to join the MInistry anymore, come to think of it….”

“Harry,” Fred began, but Harry pulled out his wand.

“Look,” he said flatly, “take it, or I’ll hex you. I know some good ones now. Just do me a favor, okay? Buy Ron some different dress robes and say they’re from you.” ~ Goblet of Fire, pp. 732-733

Sure Harry was already financially well off, but at the beginning of Goblet he coveted the prize money just as much as everyone else who wanted to compete in the Triwizard Championship.

3. The Weasley’s generosity to Harry, Hermione, and anyone in need, despite their not having a lot of money.

“It’s traditional to give a wizard a watch when he comes of age,” said Mrs. Weasley, watching him anxiously from beside the cooker. “I’m afraid that one isn’t new like Ron’s, it was actually my brother Fabian’s and he wasn’t terribly careful with his possession, it’s a bit dented on the back, but —”

The rest of her speech was lost; Harry had got up and hugged her. He tried to put a lot of unsaid things into the hug and perhaps she understood them, because she patted his cheek clumsily when he released her, then waved her wand in a slightly random way, causing half a pack of bacon to flop out of the frying pan onto the floor. ~ Deathly Hallows, p. 114

There were a lot of unsaid things in that hug because the Weasley’s had done so much more than money could buy for Harry — they gave him the love and family he never knew as a child.
Generosity comes in many forms, but it is the kind that seeks to give without getting that returns the biggest rewards.