Sahih Muslim Book 030, Hadith Number 5691.
Hadith Section/Book: Sahih Muslim Sahih Muslim Book 30. The Excellent Qualities Of The Holy Prophet (PBUH) And His Companions
Chapter : The cistern of our Apostle (may peace be upon him) and its characteristics.
The hadith has been narrated on the authority of al-A'mash with the same chain of transmitters but no mention is made of: "They are my companions; they are my companions."