Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "No man should ever have relations with a woman whose pregnancy is from someone else."
Ahmad recorded it. Its chain contains Rishdin bin Sa'd, who has been declared trustworthy, but he is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب النكاح / 7601
Hadith Gradingمحدثین:إسناده ضعیف
Hadith Takhrij«اخرجه احمد فى المسند (368/2) ، أخرجه مسند أحمد برقم: 8596»