Musnad Ahmad 28:460

Yazid ibn Harun narrated to us, Hajjaj ibn Artah informed us, from Amr ibn Shu'ayb, from his father, from his grandfather, that the Messenger of Allah (peace and blessings of Allah be upon him) returned his daughter to Abu al-Aas with a new dowry and a new marriage contract. [Abdullah ibn Ahmad said]: My father said regarding the hadith of Hajjaj: "He returned Zaynab, his daughter." He said: "This is a weak hadith," or he said: "It is flimsy (wahin), and Hajjaj did not hear it from Amr ibn Shu'ayb; he only heard it from Muhammad ibn Ubaydullah al-Arzami, and the hadith of al-Arzami is worth nothing. The authentic hadith that has been narrated is that the Prophet (peace and blessings of Allah be upon him) kept them upon the first marriage contract."