Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) said: The Jews used to say that when a man comes to a woman in her front passage from behind, the child is cross-eyed. So Allah Almighty revealed this verse: "Your wives are a tilth for you, so come to your tilth however you wish." [Surah al-Baqarah: 223]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14102