It is narrated from ‘Ikrimah (may Allah have mercy on him): Regarding the noble verse «﴿نِسَاؤُكُمْحَرْثٌلَكُمْفَأْتُواحَرْثَكُمْأَنَّىشِئْتُمْ﴾»[البقرة: 223/2] “Your wives are your fields; so come to your fields as you wish,” he said: What is meant by this is the private part (farj), i.e., have intercourse in the front, not in the back.
Hadith Referenceسنن دارمي / من كتاب الطهارة / 1160