The Book of Marriage
16/19. Chapter:
It is permissible for a man to have intercourse with his wife from the front or from the back, without entering the behind
Sahih Muslim
وَحَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ، أَخْبَرَنَا اللَّيْثُ، عَنِ ابْنِ الْهَادِ، عَنْ أَبِي حَازِمٍ، عَنْ مُحَمَّدِ، بْنِ الْمُنْكَدِرِ عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ، أَنَّ يَهُودَ، كَانَتْ تَقُولُ إِذَا أُتِيَتِ الْمَرْأَةُ مِنْ دُبُرِهَا فِي قُبُلِهَا ثُمَّ حَمَلَتْ كَانَ وَلَدُهَا أَحْوَلَ . قَالَ فَأُنْزِلَتْ { نِسَاؤُكُمْ حَرْثٌ لَكُمْ فَأْتُوا حَرْثَكُمْ أَنَّى شِئْتُمْ}
Jabir (b. Abdullah) (Allah be pleased with him) reported that the Jews used to say that when one comes to one's wife through the vagina, but being on her back, and she becomes pregnant, the child has a squint. So the verse came down: " Your wives are your ti'Ith; go then unto your tilth, as you may desire."
Reference : Sahih Muslim 1435bIn-book reference : Book 16, Hadith 138USC-MSA web (English) reference : Book 8, Hadith 3364