Sahih Muslim | Book 8 | Hadith Number 3364

Narrated by Jabir (b. Abdullah) (Allah be pleased with him)
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 tilth; go then unto your tilth, as you may desire.