كتاب النكاح
16
The Book of Marriage
(19)
Chapter: It is permissible for a man to have intercourse with his wife from the front or from the back, without entering the behind
(19)
باب جَوَازِ جِمَاعِهِ امْرَأَتَهُ فِي قُبُلِهَا مِنْ قُدَّامِهَا وَمِنْ وَرَائِهَا مِنْ غَيْرِ تَعَرُّضٍ لِلدُّبُرِ

Jabir (Allah be pleased with him) declared that the Jews used to say:

When a man has intercourse with his wife through the vagina but being on her back. the child will have squint, so the verse came down:" Your wives are your tilth; go then unto your tilth as you may desire" (ii. 223)
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، وَأَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ وَعَمْرٌو النَّاقِدُ - وَاللَّفْظُ لأَبِي بَكْرٍ - قَالُوا حَدَّثَنَا سُفْيَانُ عَنِ ابْنِ الْمُنْكَدِرِ سَمِعَ جَابرًا يَقُولُ كَانَتِ الْيَهُودُ تَقُولُ إِذَا أَتَى الرَّجُلُ امْرَأَتَهُ مِنْ دُبُرِهَا فِي قُبُلِهَا كَانَ الْوَلَدُ أَحْوَلَ فَنَزَلَتْ ‏{‏ نِسَاؤُكُمْ حَرْثٌ لَكُمْ فَأْتُوا حَرْثَكُمْ أَنَّى شِئْتُمْ‏}
Reference : Sahih Muslim 1435 a
In-book reference : Book 16, Hadith 138
USC-MSA web (English) reference : Book 8, Hadith 3363
  (deprecated numbering scheme)