Sunan an Nasai
2590
Sahih+2

It 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

SahihAbu Ghuddah
SahihAl-Albani