حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي بَكْرٍ، عَنْ عَمْرَةَ بِنْتِ عَبْدِ الرَّحْمَنِ، أَنَّ عَائِشَةَ أُمَّ الْمُؤْمِنِينَ، أَخْبَرَتْهَا أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ عِنْدَهَا وَأَنَّهَا سَمِعَتْ صَوْتَ رَجُلٍ يَسْتَأْذِنُ فِي بَيْتِ حَفْصَةَ قَالَتْ عَائِشَةُ فَقُلْتُ يَا رَسُولَ اللَّهِ هَذَا رَجُلٌ يَسْتَأْذِنُ فِي بَيْتِكَ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ أُرَاهُ فُلاَنًا ‏"‏ ‏.‏ لِعَمٍّ لِحَفْصَةَ مِنَ الرَّضَاعَةِ ‏.‏ فَقَالَتْ عَائِشَةُ يَا رَسُولَ اللَّهِ لَوْ كَانَ فُلاَنٌ حَيًّا - لِعَمِّهَا مِنَ الرَّضَاعَةِ - دَخَلَ عَلَىَّ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ نَعَمْ إِنَّ الرَّضَاعَةَ تُحَرِّمُ مَا تُحَرِّمُ الْوِلاَدَةُ ‏"‏ ‏.‏

Yahya related to me from Malik from Abdullah ibn Abi Bakr fromAmra bint Abd ar-Rahman that A'isha, umm al-muminin informed her thatthe Messenger of Allah, may Allah bless him and grant him peace, waswith her and she heard the voice of a man asking permission to enterthe room of Hafsa. A'isha said that she had said, "Messenger of Allah!There is a man asking permission to enter your house!" The Messengerof Allah, may Allah bless him and grant him peace, said, "I think itis so-and-so" (referring to a paternal uncle of Hafsa by suckling).A'isha said, "Messenger of Allah! If so-and-so were alive (referringto her paternal uncle by suckling) could he enter where I am?" TheMessenger of Allah, may Allah bless him and grant him peace, said,"Yes. Suckling makes haram as birth makes haram." Translation Not Available

Book Ref: Muwatta Imam Malik Book 30 Hadith 1275
Web Ref:  Muwatta Imam Malik Book 30 Hadith 1