It is narrated from Sayyiduna Abdullah bin al-Zubayr (may Allah be pleased with him) that Zam'ah had a slave girl with whom he had relations, and people suspected her (of immorality); then she gave birth to a child. The Prophet (peace and blessings be upon him) said: "As for the inheritance, it is his (the son of Zam'ah's) right; but as for you, O Sawdah, observe hijab from him, for he is not your brother."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13861