Bulugh al-Maram 872

Narrated 'Amr bin 'Auf al-Muzani (RA): Allah's Messenger (ﷺ) said: "Reconciliation is permissible between Muslims, except one which makes unlawful something which is lawful, or makes lawful something which is unlawful; and Muslims must abide by their conditions (which they have made), except for a condition which makes unlawful something which is lawful, or makes lawful something which is unlawful." [at-Tirmidhi reported it and graded it Sahih (authentic)]. However, the Hadith scholars criticized him (for grading this Hadith as Sahih) because the narration of Kathir bin 'Abdullah bin 'Amr bin 'Auf is weak. It is as though at-Tirmidhi considered it (reliable) due to its many chains of narration. Ibn Hibban declared the aforesaid Hadith to be Sahih (authentic) from the narration of Abu Hurairah (RA).