Sahih Muslim
The Book of Fasting (Kitab Al-Sawm)
Book Number: 006 / Hadith Number: 2560
Ibn Buraida (Allah be pleased with him) reported on the authority of his father: A woman came to the Apostle of Allah (may peace be upon him), and the rest of the hadith is the same, but he said:" Fasting of one month." This hadith has been narrated on the authority of Sufyan with the same chain of transmitters in which it is said:" Fasting of two months."