It was narrated from 'Irak bin Malik that Zainab bint Abi Salamah told him, that Umm Habibah said to the Messenger of Allah:
We have been saying that you want to marry Durrah bint Abi Salamah. The Messenger of Allah said: As a co-wife to Umm Salamah? Even if I were not married to Umm Salamah, she would not be permissible to me, for her father is my brother through breast-feeding.