Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates that the Prophet (peace and blessings be upon him) said: "The wrath of Allah Almighty is severe upon a woman who brings into a people someone who is not from them (that is, gives birth to an illegitimate child), so that he becomes acquainted with their private matters and becomes their partner in their wealth."
Al-Bazzar recorded it, and al-Tabarani in al-Mu'jam al-Awsat; its chain contains a narrator, Ibrahim bin Yazid, and he is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الفرائض / 7146