"I heard the Messenger of Allah say: 'I wanted to forbid intercourse with a nursing mother, but then (I saw that) the Persians and the Romans do this, and it does not kill their children.' And I heard him say/when he was asked about coitus interruptus: 'It is the disguised form of b.rryirg children alive."  

أَنَّهَا قَالَتْ سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ قَدْ أَرَدْتُ أَنْ أَنْهَى عَنِ الْغِيَالِ فَإِذَا فَارِسُ وَالرُّومُ يُغِيلُونَ فَلاَ يَقْتُلُونَ أَوْلاَدَهُمْ وَسَمِعْتُهُ يَقُولُ وَسُئِلَ عَنِ الْعَزْلِ فَقَالَ هُوَ الْوَأْدُ الْخَفِيُّ  

she heard the Messenger of Allah say: "Do not kill your children secretly, for by the One in Whose Hand is my soul, intercourse with a breastfeeding woman catches up with people when they are riding their horses (in battle) and wrestles them to the ground."  

أَنَّهَا سَمِعَتْ رَسُولَ اللَّهِ ﷺ يَقُولُ لاَ تَقْتُلُوا أَوْلاَدَكُمْ سِرًّا فَوَالَّذِي نَفْسِي بِيَدِهِ إِنَّ الْغَيْلَ لَيُدْرِكُ الْفَارِسَ عَلَى ظَهْرِ فَرَسِهِ حَتَّى يَصْرَعَهُ