Musannaf Ibn Abi Shaybah

Hazrat Muhammad bin Ibrahim Taimi says that Utbah bin Abi Sufyan had four wives in his marriage. He divorced one and married a fifth before the waiting period (‘iddah) of the divorced wife was completed. Marwan asked Hazrat Ibn Abbas (may Allah be pleased with them both) about this, so he replied that one cannot marry a fifth before the waiting period of the fourth is completed.