As legend goes, the origin of this event is that Eison dedicated tea to Chinju-Hachimangu Shrine of Saidai-ji Temple and entertained visitors with tea that had been offered.
叡尊が西大寺の鎮守八幡宮に茶を奉納し、お下がりの茶を参詣人にふるまったのが起源とされる。