Abu Dawud Book 6, Hadith Number 2188.

Narated By ‘Aisha, Ummul Mu’minin : Muhammad ibn Ubayd ibn AbuSalih who lived in Ayliya said: I went out with Adi ibn Adi al-Kindi till we came to Mecca. He sent me to Safiyyah daughter of Shaybah who remembered a tradition (that she had heard) from ‘Aisha. She said: I heard ‘Aisha say: I heard the Apostle of Allah (PBUH) say: There is no divorce or emancipation in case of constraint or duress (ghalaq).