Hadith 10:191
Abu Bakr narrated to us, he said: Abu Bakr al-Hanafi narrated to us, from Usama, from Nafi’, that al-Mughira ibn ‘Abd al-Rahman divorced his wife while he was mentally deficient (ma’tuh). Ibn ‘Umar ordered that she observe the waiting period (‘idda). It was said to him, "He is mentally deficient." He said, "I have not heard that Allah exempted a mentally deficient person from divorce, nor anything else."
حدثنا أبو بكر قال حدثنا أبو بكر الحنفي عن أسامة عن نافع أن المغيرة بن عبد الرحمن طلق امرأته وهو معتوه فأمر بن عمر أن تعتد فقيل له إنه معتوه فقال إني لم أسمع الله استثنى لمعتوه طلاقا ولا غيره