كتاب النكاح
16
The Book of Marriage
(22)
Chapter: The ruling on coitus interrupts ('Azl)
(22)
باب حُكْمِ الْعَزْلِ ‏
Sahih Muslim 1438 c

Abu Sa'id al-Khudri (Allah be pleased with him) reported:

We took women captives, and we wanted to do 'azl with them. We then asked Allah's Messen- ger (ﷺ) about it, and he said to us: Verily you do it, verily you do it, verily you do it, but the soul which has to be born until the Day of judg- ment must be born.
حَدَّثَنِي عَبْدُ اللَّهِ بْنُ مُحَمَّدِ بْنِ أَسْمَاءَ الضُّبَعِيُّ، حَدَّثَنَا جُوَيْرِيَةُ، عَنْ مَالِكٍ، عَنِ الزُّهْرِيِّ، عَنِ ابْنِ مُحَيْرِيزٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، أَنَّهُ أَخْبَرَهُ قَالَ أَصَبْنَا سَبَايَا فَكُنَّا نَعْزِلُ ثُمَّ سَأَلْنَا رَسُولَ اللَّهِ صلى الله عليه وسلم عَنْ ذَلِكَ فَقَالَ لَنَا ‏ "‏ وَإِنَّكُمْ لَتَفْعَلُونَ وَإِنَّكُمْ لَتَفْعَلُونَ وَإِنَّكُمْ لَتَفْعَلُونَ مَا مِنْ نَسَمَةٍ كَائِنَةٍ إِلَى يَوْمِ الْقِيَامَةِ إِلاَّ هِيَ كَائِنَةٌ ‏"‏ ‏.‏
Reference : Sahih Muslim 1438 c
In-book reference : Book 16, Hadith 149
USC-MSA web (English) reference : Book 8, Hadith 3373
  (deprecated numbering scheme)