Yahya related to me from Malik from Nafi that Abdullah ibn Umarused to say, "There is no harm in doing ghusl with water that has beenused by one's wife as long as she is not menstruating or in a state ofmajor ritual impurity (junub)."
USC-MSA web (English) reference: Book 2, Hadith 88
Arabic reference: Book 2, Hadith 118