ENOfficial
It was narrated from Ibn 'Abbas: that the Messenger of was offered the daughter of Hamzah bin 'Abdul-Muttalib in marriage, and he said: “She is the daughter of my brother through breastfeeding, and breastfeeding makes unlawful (for marriage) the same things that blood ties make unlawful.”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا حُمَيْدُ بْنُ مَسْعَدَةَ، وَأَبُو بَكْرِ بْنُ خَلاَّدٍ قَالاَ حَدَّثَنَا خَالِدُ بْنُ الْحَارِثِ، حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنْ جَابِرِ بْنِ زَيْدٍ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ أُرِيدَ عَلَى بِنْتِ حَمْزَةَ بْنِ عَبْدِ الْمُطَّلِبِ فَقَالَ " إِنَّهَا ابْنَةُ أَخِي مِنَ الرَّضَاعَةِ وَإِنَّهُ يَحْرُمُ مِنَ الرَّضَاعَةِ مَا يَحْرُمُ مِنَ النَّسَبِ " .
sunnah.com