Sahih Muslim
The Book of Faith (Kitab Al-Iman)
Book Number: 001 / Hadith Number: 364
Sha'bi reported he had heard al-Mughira b. Shu'ba say on the pulpit that Moses (peace be upon him) had asked Allah, Exalted and Great, about the reward of the lowest of the inhabitants of Paradise, and the remaining part of hadith is the same (as narrated) above.