Sunan Ibn Majah, Hadith 1925

It was narrated from Muhammad bin Munkadir: that he heard Jabir bin 'Abdullah say: “The Jews used to say that if a man has intercourse with a woman in her vagina from the back, the child would have a squint. Then Allah, Glorious is He, revealed: 'Your wives are a tilth for you, so go to your tilth, when or how you will.' ”

حَدَّثَنَا سَهْلُ بْنُ أَبِي سَهْلٍ، وَجَمِيلُ بْنُ الْحَسَنِ، قَالاَ حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ مُحَمَّدِ بْنِ الْمُنْكَدِرِ، أَنَّهُ سَمِعَ جَابِرَ بْنَ عَبْدِ اللَّهِ، يَقُولُ كَانَتْ يَهُودُ تَقُولُ مَنْ أَتَى امْرَأَةً فِي قُبُلِهَا مِنْ دُبُرِهَا كَانَ الْوَلَدُ أَحْوَلَ فَأَنْزَلَ اللَّهُ سُبْحَانَهُ ‏{نِسَاؤُكُمْ حَرْثٌ لَكُمْ فَأْتُوا حَرْثَكُمْ أَنَّى شِئْتُمْ}‏ ‏.‏

sunnah.com