When the Buddha was at the Ajapālanigrodha, hesitating as to whether or not he should preach the Dhamma, Sahampati appeared before him and begged of him to open to the world the doors of Immortality. The Buddha agreed to this urgent request (Vin.i.5f.;S.i.137f), and accepted from Sahampati the assurance that all the Buddhas of the past had also had no other teacher than the Dhamma discovered by them. S.i.139; see also S.v.167f.,185, 232, where he gives the same assurance to the Buddha regarding the four satipatthānas and the five indriyas; A.ii.10f.