It was narrated that 'Ali, may Allah be pleased with him, said: "I said: 'O Messenger of Allah, why do you choose wives from among Quraish and not from among us?' He said: 'Do you have anyone in mind?' I said: 'Yes, the daughter of Hamzah.' The Messenger of Allah (ﷺ) said: 'She is not permissible for me (to marry); she is the daughter of my brother through breast-feeding.'"
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا هَنَّادُ بْنُ السَّرِيِّ، عَنْ أَبِي مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ سَعْدِ بْنِ عُبَيْدَةَ، عَنْ أَبِي عَبْدِ الرَّحْمَنِ السُّلَمِيِّ، عَنْ عَلِيٍّ، رضى الله عنه قَالَ قُلْتُ يَا رَسُولَ اللَّهِ مَا لَكَ تَنَوَّقُ فِي قُرَيْشٍ وَتَدَعُنَا قَالَ " وَعِنْدَكَ أَحَدٌ " . قُلْتُ نَعَمْ بِنْتُ حَمْزَةَ . قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّهَا لاَ تَحِلُّ لِي إِنَّهَا ابْنَةُ أَخِي مِنَ الرَّضَاعَةِ " .
sunnah.com