Nafi reported,

Whenever Ibn Umar recited the Quran, he would not speak. The narrator said, One day I recited this verse, "Your wives are a tilth for you, so come to your tilth as you wish" [Baqarah 2:223].Ibn Umar asked, "Do you know about whom this verse was revealed?"I replied, "No."He said, "It was revealed concerning approaching women in their backsides."

Azami 12006

Sahih

عن نافع قال

كان ابن عمر إذا قرأ القرآن لم يتكلم قال: فقرأت ذات يوم هذه الآية: {نساؤكم حرث لكم فأتوا حرثكم أنى شئتم} فقال: أتدري فيمن نزلت هذه الآية؟ قلت: لا، قال: نزلت في إتيان النساء في أدبارهن.

الأعظمي 12006صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Tafsir of the great Quran
Chapter
Virtues of Surah Baqarah
Section
His saying, "Your women are a tilth for you, so come to your tilth however you wish, and send forth for yourselves, and fear Allah, and know that you will meet Him, and give glad tidings to the believers"
Numbering
Jami al-Kamil 12006 (2nd edition)
Azami 12006