One morning Upatissa was walking towards Rajagaha. On the way there he met a monk. He looked very peaceful and seemed to be free from all fear. This monk was Arahant Assaji. Upatissa went towards him and said: "Venerable master! Who is your teacher and what did he teach you?" The monk replied with a smile: "My teacher is a great sage of the Sakya Clan. He is the Buddha and I practice according to his teaching."