Sahih Bukhari Volume 3, Book 34, Hadith 2230

حَدَّثَنَا أَبُو الْيَمَانِ، أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ أَخْبَرَنِي ابْنُ مُحَيْرِيزٍ، أَنَّ أَبَا سَعِيدٍ الْخُدْرِيَّ ـ رضى الله عنه ـ أَخْبَرَهُ أَنَّهُ، بَيْنَمَا هُوَ جَالِسٌ عِنْدَ النَّبِيِّ صلى الله عليه وسلم قَالَ يَا رَسُولَ اللَّهِ إِنَّا نُصِيبُ سَبْيًا، فَنُحِبُّ الأَثْمَانَ، فَكَيْفَ تَرَى فِي الْعَزْلِ فَقَالَ ‏"‏ أَوَإِنَّكُمْ تَفْعَلُونَ ذَلِكَ لاَ عَلَيْكُمْ أَنْ لاَ تَفْعَلُوا ذَلِكُمْ، فَإِنَّهَا لَيْسَتْ نَسَمَةٌ كَتَبَ اللَّهُ أَنْ تَخْرُجَ إِلاَّ هِيَ خَارِجَةٌ ‏"‏‏.‏

Narrated By Abu Said Al-Khudri : That while he was sitting with Allah's Apostle he said, "O Allah's Apostle! We get female captives as our share of booty, and we are interested in their prices, what is your opinion about coitus interrupt us?" The Prophet said, "Do you really do that? It is better for you not to do it. No soul that which Allah has destined to exist, but will surely come into existence.