We took captives on the day of Hunayn and were hoping to receive ransom for them, so we asked the Messenger of Allah ﷺ about coitus interruptus. He said, "Do as you wish. Whatever Allah has decreed will come to pass, for not every emission of fluid produces a child."
حدثنا وكيع عن يونس بن عمرو عن أبي الوداك
أصبنا سبيا يوم حنين فكنا نلتمس فداءهن فسألنا رسول الله ﷺ عن العزل فقال اصنعوا ما بدا لكم فما قضى الله فهو كائن فليس من كل الماء يكون الولد
Its isnad is sahih. Its narrators are reliable and have been mentioned before, and the hadith has previously appeared at 11115.