Sahih Bukhari Volume 006, Book 060, Hadith Number 050.
Narrated By Nafi' : Whenever Ibn 'Umar recited the Qur'an, he would not speak to anyone till he had finished his recitation. Once I held the Qur'an and he recited Surat-al-Baqara from his memory and then stopped at a certain Verse and said, "Do you know in what connection this Verse was revealed? " I replied, "No." He said, "It was revealed in such-and-such connection." Ibn 'Umar then resumed his recitation. Nafi added regarding the Verse: "So go to your tilth when or how you will" Ibn 'Umar said, "It means one should approach his wife in..."