Musannaf Ibn Abi Shayba 9:844

'Abbad ibn al-'Awwam narrated to us, from 'Abd al-Malik, from 'Ata', that he was asked about a man who had four wives and divorced one of them three times: "May he marry a fifth?" He said: "No, not until the waiting period ('iddah) of the one he divorced has expired."