Truly, just like you said, true giving doesn't imply that you have things enough and in excess. It only entails that you have a kind heart. And even the universe blessed givers.

We are encouraged to give more than we receive. A divine instruction like the one your Dad followed is something that must be followed through to the end - it may not make sense all the way, but just believe and do it.

And you don't necessarily have to start calculating what gains you will amass from that act. My code for natural giving is to give if you have and don't expect anything in return..even a subconscious 'thank you', because low key we all still want that phrase of appreciation.