How does organ donation provide an opportunity for a final act of tzedakah that another person will never be able to repay?

תַּנְיָא נָמֵי הָכִי: תְּשַׁע מֵאוֹת וּשְׁלֹשָׁה מִינֵי מִיתָה נִבְרְאוּ בָּעוֹלָם, שֶׁנֶּאֱמַר: ״לַמָּוֶת תּוֹצָאוֹת״, ״תּוֹצָאוֹת״ בְּגִימַטְרִיָּא הָכִי הָווּ.
It was also taught in a baraita: Nine hundred and three types of death were created in the world, as it is stated: “Issues [totzaot] of death,” and that, 903, is the numerical value [gimatriya] of totzaot.
1. Sherwin Nuland, How We Die: Reflections on Life’s Final Chapter
"Every life is different from any that has gone before it, and so is every death. The uniqueness of each of us extends even to the way we die. Though most people know that various diseases carry us to our final hours by various paths, only very few comprehend the fullness of that endless multitude of ways by which the final forces of the human spirit can separate themselves from the body. Every one of death’s diverse appearances is as distinctive as that singular face we each show the world during the days of life."
2. Peter Singer, The Life You Can Save: Acting Now to End World Poverty
"Suppose you have just sent $200 to an agency that can, for that amount, save the life of a child in a developing country who would otherwise have died. You’ve done something really good, and all it has cost you is the price of some new clothes you didn’t really need anyway. Congratulations! But don’t celebrate your good deed by opening a bottle of champagne, or even going to a movie. The cost of that bottle or movie, added to what you could save by cutting down on a few other extravagances, would save the life of another child. After you forgo those items, and give another $200, though, is everything else you are spending on as important, or nearly as important, as the life a child? Not likely! So you must keep cutting back on unnecessary spending, and donating what you save, until you have reduced yourself to the point where if you give any more, you will be sacrificing something nearly as important as a child’s life--like giving so much that you can no longer afford to give your children an adequate education.
...if the basic argument presented above is right, then what many of us consider acceptable behavior must be viewed in a new, more ominous light. When we spend our surplus on concerts or fashionable shoes, on fine dining and good wines, or holidays in faraway lands, we are doing something wrong."


