Sahih Al Bukhari Hadith Number 1951

Narrated Abu Sa`id: The Prophet (peace be upon him) said, “Isn’t it true that a woman does not pray and does not fast on menstruating? And that is the defect (a loss) in her religion.”

30  Fasting
Hadith number 1951
Volume no 3
Chapter: 41 (The menstruating should leave the Saum and Salat)