The Book of Marriage
26/51. Chapter:
The Amount Of Breast-feeding That Makes Marriage Prohibited
Sunan an-Nasai
أَخْبَرَنَا شُعَيْبُ بْنُ يُوسُفَ، عَنْ يَحْيَى، عَنْ هِشَامٍ، قَالَ حَدَّثَنِي أَبِي، عَنْ عَبْدِ اللَّهِ بْنِ الزُّبَيْرِ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ تُحَرِّمُ الْمَصَّةُ وَالْمَصَّتَانِ " .
It was narrated from 'Abdullah bin Az-Zubair that the Prophet said: "Suckling once or twice does not make (marriage) prohibited."
Reference : Sunan an-Nasa'i 3309In-book reference : Book 26, Hadith 114English translation : Vol. 4, Book 26, Hadith 3311