Sahih Muslim
The Book of Fasting (Kitab Al-Sawm)
Book Number: 006 / Hadith Number: 2540
Nabaisha reported that Khalid said: I met Abu Malih and asked him and he narrated it to me from the Apostle of Allah (may peace be upon him). a hadith like one (narrated above) with this addition:" And remembrance of Allah"