What is the source for this "deeds transfer" story?

I have been told this story multiple times by Muslims, and I am looking for the source for this story. The story goes something like this: There is a guy with many more bad deeds than a good deeds, and there is another guy with almost half good/bad, but with one more bad deed. The guy with many bad deeds sees the guy with 50%-50% -1, and he decides to give his good deeds so that the other guy can go to heaven. Then the ~50%-50% guy goes to heaven because now he has more good than bad deeds, and Allah sees the kindness/generosity/mercy of the guy who donated his good deeds, though he had many more bad than good deeds, and Allah decides to grant him mercy as well and he is allowed into heaven. 1. Is this story in the Quran, hadith or neither? 2. If so, where?