What episode of Naruto was hit on the back by four generations of Naruto?

Four generations and Dai Tu are also apprentices, but the four generations didn't know at that time, and Dai Tu knew that it was his teacher in front.

: The character in the Japanese anime Naruto, the fourth generation of Muyingyin Village in the fire country, the disciple of Jiraiya, one of Muyingyin's three forbearance, and the father of the protagonist Naruto Usagi. He is calm and wise, good at developing and improving Ninjutsu, powerful and the highest speed, and is known as "Yellow Flash". During Kyubi no Youko's attack on Konoha, he died to protect the village and sealed Kyubi no Youko with a ghost.