Muhammad bin Sirin (may Allah have mercy on him) said that Sayyiduna Umar bin al-Khattab (may Allah be pleased with him), while seated on the pulpit, said: Do you know how many (wives) a slave may marry? A man stood up and said: I know. He asked: How many? He said: Two. Others have added more to it: but Sayyiduna Umar (may Allah be pleased with him) remained silent. He said: Then a man of the Ansar stood up.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13896