Sahih Muslim
The Book of Fasting (Kitab Al-Sawm)
Book Number: 006 / Hadith Number: 2460
This hadith has been narrated on the authority of Zuhri with the same chain of transmitters that a person broke fast in Ramadan whereupon the Messenger of Allah (may peace be upon him) commanded him to free a slave (as an atonement), and the rest of the hadith is the same as narrated by Ibn Uyaina.