Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) said: The Jews used to say that when a man has intercourse with his wife in the private part from behind, the child is born cross-eyed. This was mentioned to the Prophet (peace and blessings be upon him), and this verse was revealed: "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 / 14101