It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that Sayyiduna Umar (may Allah be pleased with him) came to the Noble Prophet (peace and blessings be upon him) and said, "O Messenger of Allah! I have been ruined." The Prophet (peace and blessings be upon him) asked, "What has ruined you?" He replied, "Last night I had intercourse with my wife from behind in her front private part." The Prophet (peace and blessings be upon him) did not give him any answer, so Allah Almighty revealed this verse to His Prophet (peace and blessings be upon him): {نِسَاؤُکُمْ حَرْثٌ لَّکُمْ فَاْتُوْا حَرْثَکُمْ اَنّٰی شِئْتُمْ} ... "Your wives are your fields; so come to your fields as you wish." But only one opening should be used. (Surah Al-Baqarah: 223) Then the Prophet (peace and blessings be upon him) said, "Come from the front or from behind, but avoid intercourse in the anus and during menstruation."