Zaynab bint Abi Salamah narrates that Umm Habibah (may Allah be pleased with her) said to the Messenger of Allah (peace and blessings be upon him): We have been saying that you are going to marry Durrah bint Abi Salamah. He (peace and blessings be upon him) said: "While Umm Salamah is with me? Even if I had not married Umm Salamah, she would not be lawful for me, for her father is my foster brother."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19723