What is the source of this popular quote about giving? What is the source of the following quote (rightly or wrongly) attributed to the historical Buddha (easily found online):

Generosity brings happiness at every stage of its expression. We
experience joy in forming the intention to be generous. We experience
joy in the actual act of giving something. And we experience joy in
remembering the fact that we have given.
At least parts of the quote appears to originate from the article &quot;Family Dharma: The Joy of Generosity&quot;, written by Beth Roth and published in January 2007. This article appears in &quot;Tricycle: The Buddhist Review&quot;, a Buddhist magazine.
I guess from there, it became wrongly attributed to the Buddha and the text has also changed along the way.
If you read the article, Beth Roth derived her inspiration from the Buddha, as shown below.

The Buddha said, “If you knew, as I do, the power of giving, you would
not let a single meal pass without sharing some of it.”

This comes from Iti 26:

This was said by the Blessed One, said by the Arahant, so I have
heard: &quot;If beings knew, as I know, the results of giving &amp; sharing,
they would not eat without having given, nor would the stain of
selfishness overcome their minds. Even if it were their last bite,
their last mouthful, they would not eat without having shared, if
there were someone to receive their gift. But because beings do not
know, as I know, the results of giving &amp; sharing, they eat without
having given. The stain of selfishness overcomes their minds.&quot;

Also, related quote from AN 3.57:

&quot;I tell you, Vaccha, even if a person throws the rinsings of a bowl or
a cup into a village pool or pond, thinking, 'May whatever animals
live here feed on this,' that would be a source of merit, to say
nothing of what is given to human beings. But I do say that what is
given to a virtuous person is of great fruit, and not so much what is
given to an unvirtuous person.