The Book of Marriage
16/24. Chapter:
It is permissible to have intercourse with a breastfeeding woman (Ghilah), and 'Azl is disliked
Sahih Muslim
وَحَدَّثَنَا خَلَفُ بْنُ هِشَامٍ، حَدَّثَنَا مَالِكُ بْنُ أَنَسٍ، ح وَحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، - وَاللَّفْظُ لَهُ - قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ نَوْفَلٍ عَنْ عُرْوَةَ عَنْ عَائِشَةَ عَنْ جُدَامَةَ بِنْتِ وَهْبٍ الأَسَدِيَّةِ أَنَّهَا سَمِعَتْ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " لَقَدْ هَمَمْتُ أَنْ أَنْهَى عَنِ الْغِيلَةِ حَتَّى ذَكَرْتُ أَنَّ الرُّومَ وَفَارِسَ يَصْنَعُونَ ذَلِكَ فَلاَ يَضُرُّ أَوْلاَدَهُمْ " . قَالَ مُسْلِمٌ وَأَمَّا خَلَفٌ فَقَالَ عَنْ جُذَامَةَ الأَسَدِيَّةِ . وَالصَّحِيحُ مَا قَالَهُ يَحْيَى بِالدَّالِ .
Judaima daughter of Wahb al-Asadiyya (Allah be pleased with her) reported that she heard Allah's Messenger (ﷺ) assaying: I intended to prohibit cohabitation with a suckling woman until I considered that the Romans and the Persians do it without any injury being caused to their children thereby. (Imam Muslim said: Khalaf reported it from Judamat al-'Asadiyya, but the correct wording is what has been stated by Yahya.)
Reference : Sahih Muslim 1442aIn-book reference : Book 16, Hadith 166USC-MSA web (English) reference : Book 8, Hadith 3391