It was narrated from Anas that:
The Jews would not sit with a menstruating woman in a house, nor eat with her, nor drink with her. That was mentioned to the Messenger of Allah, then Allah revealed the words: "They ask you concerning menstruation. Say: that is a harmful thing, therefore keep away from women during menses." The Messenger of Allah said: "Do everything except sexual intercourse." (FR)
English reference (FR): Vol. 1, Book 1, Hadith 644 (FR)
Arabic reference (FR): Book 1, Hadith 687 (FR)