Sunan an-Nasa'i 2590
سنن النسائي#2590SahihIt was narrated that Thawban said:"The Messenger of Allah said: 'Whoever can promise me one thing. Paradise will be his." (One of the narrators) Yahya said: "Here a statement which means: That he will not ask the people for anything
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 23:156