Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: Sayyiduna Umar bin Khattab (may Allah be pleased with him) came to the service of the Prophet (peace and blessings be upon him) and said: I have been ruined. The Prophet (peace and blessings be upon him) asked: What has caused your ruin? He replied, Last night I turned my saddle upside down. The narrator says, so the Prophet (peace and blessings be upon him) did not give any answer. Allah Almighty revealed this to the Prophet (peace and blessings be upon him): "Your wives are your tilth; so come to your tilth as you wish." The narrator states: That is, whether you come from the front or from the back, but avoid the anus and during menstruation.
Hadith Referenceصحیح ابن حبان / كتاب النكاح / 4202
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيحسن - «آداب الزفاف» (28 - 29).فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده حسن