Musnad Ahmad 620
It was narrated that ‘Ali (رضي الله عنه) said:
O Messenger of Allah (ﷺ), why do you choose to get married from among Quraysh and you ignore us? He said: `Have you anybody to suggest?` I said: Yes, the daughter of Hamzah. The Messenger of Allah (ﷺ)  said: `She is not permissible for me (to marry), for she is the daughter of my brother through breastfeeding.`
حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الْأَعْمَشِ، عَنِ سَعْدِ بْنِ عُبَيْدَةَ، عَنْ أَبِي عَبْدِ الرَّحْمَنِ السُّلَمِيِّ، عَنْ عَلِيٍّ، رَضِيَ اللَّهُ عَنْهُ قَالَ قُلْتُ يَا رَسُولَ اللَّهِ مَا لَكَ تَنَوَّقُ فِي قُرَيْشٍ وَتَدَعُنَا قَالَ وَعِنْدَكُمْ شَيْءٌ قَالَ قُلْتُ نَعَمْ ابْنَةُ حَمْزَةَ قَالَ إِنَّهَا لَا تَحِلُّ لِي هِيَ ابْنَةُ أَخِي مِنْ الرَّضَاعَةِ‏.‏