Sunan Abu Dawud
2219
Sahih+2

Narrated Hisham b. 'Urwah: Khawlah was the wife of Aws ibn as-Samit; he was a man immensely given to sexual intercourse. When his desire for intercourse was intensified, he made his wife like his mother's back. So Allah, the Exalted, sent down Qur'anic verses relating to expiation for zihar

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid