Mishkat al-Masabih 2802

‘Amr b. ‘Auf al-Muzani reported the Prophet as saying, “Reconciliation is allowable between Muslims except such as makes unlawful something which is lawful, or makes lawful something which is unlawful ; and Muslims must keep to the conditions they have made, except for a condition which makes unlawful something which is lawful, or makes lawful something which is unlawful.” Tirmidhi, Ibn Majah and Abu Dawud transmitted it, but Abu Dawud's transmission ended at “the conditions they have made.”