How did the white rabbit become the ritual object?

How did the white rabbit become the ritual object? Tho Trang is a ritual object during the Mid-Autumn Festival.

Once upon a time, there lived a hardworking, brave and kind-hearted white rabbit called Tho trang. One moonlit night in the forest, Tho Trang and his friends held a party to welcome the moon. Suddenly they heard a scream. They ran to check and found an old man fainting from hunger. While they were trying to help the man, a cuiTning fox stole all the food they had laid out for the party.

Tho Trang and his friends searched for food to give the man. Alas, they found nothing. Brave Tho Trang jumped into the fire to roast himself as food to save the man. However, it turned out that the old man was a fairy, who had disguised himself as a beggar to test the kindness of children. The fairy was so moved by Tho Trang's self-sacrifice that he took the rabbit with him to the moon. Tho Trang has since become a ritual object during the Mid-Autumn Festival.