Sahih Muslim
The Book Pertaining to Piety and Softening of Hearts (Kitab Al-Zuhd wa Al-Raqaiq)
Book Number: 042 / Hadith Number: 7117
Sufyan reported this hadith with the same chain of transmitters and he made this addition:" I did not hear anyone saying besides him that it was Allah's Messenger (may peace be upon him) who had said so."