Sahih al-Bukhari 4528

Arabic

حَدَّثَنَا أَبُو نُعَيْمٍ، حَدَّثَنَا سُفْيَانُ، عَنِ ابْنِ الْمُنْكَدِرِ، سَمِعْتُ جَابِرًا ـ رضى الله عنه ـ قَالَ كَانَتِ الْيَهُودُ تَقُولُ إِذَا جَامَعَهَا مِنْ وَرَائِهَا جَاءَ الْوَلَدُ أَحْوَلَ‏.‏ فَنَزَلَتْ ‏{‏نِسَاؤُكُمْ حَرْثٌ لَكُمْ فَأْتُوا حَرْثَكُمْ أَنَّى شِئْتُمْ‏}‏

English translation

Narrated Jabir:Jews used to say: "If one has sexual intercourse with his wife from the back, then she will deliver a squint-eyed child." So this Verse was revealed:-- "Your wives are a tilth unto you; so go to your tilth when or how you will

Reference: Sahih al-Bukhari 4528, Book of Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)). English translation by Dr. Muhammad Muhsin Khan.