Abdur Rahman bin Sabit says: I went to Sayyidah Hafsah bint Abdur Rahman (may Allah be pleased with her) and said: I want to ask you a question, but modesty prevents me. She said: Nephew, do not be shy. I said, the issue is about intercourse with women from their back passage. She said: Sayyidah Umm Salamah (may Allah be pleased with her) narrated to me that the Ansar did not lay women face down during intercourse, because the Jews used to say that if a woman is laid face down during intercourse, a cross-eyed child is born. When the Muhajirun came to Madinah and married the women of the Ansar and wanted to have intercourse with them face down, an Ansari woman refused to comply with her husband and said: You will never be able to do this until I ask the Prophet Muhammad (peace and blessings be upon him) about it. So she went to Sayyidah Umm Salamah (may Allah be pleased with her) and mentioned this matter to her. She said: Sit down, stay here until the Prophet Muhammad (peace and blessings be upon him) arrives. When he (peace and blessings be upon him) came, the Ansari woman was too shy to ask and went outside. When Sayyidah Umm Salamah (may Allah be pleased with her) asked the Prophet Muhammad (peace and blessings be upon him) about this, he (peace and blessings be upon him) said: Call that Ansari woman. So when she was called, he (peace and blessings be upon him) recited this verse to her: {نِسَاؤُکُمْ حَرْثٌ لَّکُمْ فَاْتُوْا حَرْثَکُمْ اَنّٰی شِئْتُمْ} (Surah Al-Baqarah: 223) ... Your wives are your fields, so come to your fields as you wish. But only one opening should be used.