The story goes as follows:
A butcher ran into two people who were cultivating Buddhahood. The two people said that they were on their way to the West to see the Buddha, and tried to convince the butcher to go with them.
The butcher said, "I'm just too filthy and not worthy. But please, take my sincere heart with you." (This showed that even though this person's profession was not good, he still had the sincere heart to respect and long for the Buddha.)
So the butcher took out his own heart and gave it to the two people. (This showed that the butcher had no reservations or doubts about his respect and longing for the Buddha.)
The two people who were cultivating Buddhahood agreed and took his heart to the West. After they came into the Buddha's presence, the Buddha pointed to a giant pot filled with boiling water and asked them if they dared to jump in.
The two people both felt a lot of hesitation, so they thought: Maybe it would be best to throw that heart into the pot and see what happens? (This showed that these two cultivators did not have complete faith in the Buddha's words and were still evaluating them with a human heart.)
So they threw the butcher's heart into the pot, and it became a golden Buddha. (A reflection of the state of that person's inner being's realm.)
Seeing this, the two people immediately jumped in, too. (This showed that these two people had very poor enlightenment quality and were stuck in the mentality of "seeing is believing." They only did what the Buddha said to do when they saw the gains they were after.)
The outcome was that they became two pieces of fried dough, the reflection of their inner being's realm.