Hadith 10:613
Abu Bakr narrated to us, he said: Abd al-Rahim ibn Sulayman narrated to us, from Sa’id, from Qatadah, from al-Hasan, and from Abu Ma’shar, from Ibrahim, they both said: If a man says to his wife, "If I approach you, then you are to me like the back of my mother," and he approaches her within four months, then it is *zihar* (injurious assimilation), and a time limit has been set for it. And if he does not approach her until four months have passed, then it is *ila* (vow of abstention), and she has become irrevocably separated from him by one [divorce].
حدثنا أبو بكر قال نا عبد الرحيم بن سليمان عن سعيد عن قتادة عن الحسن وعن أبي معشر عن إبراهيم قالا إذا قال الرجل لأمرأته إن قربتك فأنت علي كظهر أمي فإن قربها في أربعة أشهر فهو ظهار وقد وقت عليه وإن لم يقربها حتى تمضي أربعة أشهر فهو إيلاء وقد بانت منه بواحدة