Many centuries ago a Chinese monk named Mu Lien achieved Nirvana. He had studied, meditated and prayed very hard for many lifetimes so he would no longer need to be reborn in this world of pain and sorrow.
Having achieved Nirvana, Mu Lien wished to give his blessing to his parents. Using his great powers he searched for his parents and was shocked to find that they had died and become restless ghosts searching for food offered by those who remember the dead.
Mu Lien quickly brought them two large bowls of food. But when they lifted the bowls to their lips the rice became burning coals so they could not eat. In deep distress Mu Lien went to the Buddha to ask why this happened.
The Buddha told Mu Lien that his parents had done some very bad things in their previous lives and their Karma was to suffer as hungry ghosts. Mu Lien was very upset to hear this. He offered to do anything he could to help his parents.
The Buddha told him that Karma builds up over many lifetimes and can’t be easily changed. Mu Lien felt very sad and began to cry.
Then the Buddha told him that Mo Sheh, a wise man from Kaifeng in northern China, once explained to the Buddha that the gates of repentance are always open. If Mu Lien could get 10 monks to join him on the full moon that falls on the 15th day of the 7th month, to eat and drink together outdoors for a full week, the power of bad Karma would be broken.
According to Chinese legend, Mu Lien did gather together monks from ten different quarters of China. On the full moon of the 15th day of the 7th month, they ate and drank outdoors together for a full week as the Buddha had told Mu Lien to do.
Since that time, thousands of Buddhist monks in China each year honor their parents on the full moon of the 15th day of the 7th month. These Chinese monks honor their ancestors at the same calendar time as Jewish people around the world honor their departed ancestors by saying Kaddish during the Yiskor services on the last day of the week of Sukkot, and like Jews celebrating in a Sukkah the monks sit outdoors eating and drinking.
Did the Buddha learn all this from Moses? Or was the wise man a Rabbi Moshe from the synagogue in Kaifeng. After all, After all, the prophet Zechariah (14:16) said one someday all nations (even our attackers) would come to worship the Lord, and keep the Feast of Tabernacles in Jerusalem.