It is reported that ʿAlī b. Al-Ḥusayn b. ʿAlī b.ʾAbī Ṭālib – Allāh have mercy on him – said:

No man speaks well about another while not knowing it to be true except that he is also likely to speak badly about him without knowing it to be true. And two people do not accompany each other doing something that is not obedience to Allāh except that it is likely they will part from each other doing something that is not obedience to Allāh.

Abū Bakr Al-Daynūrī, Al-Mujālasah wa Jawāhir Al-ʿIlm 5:274 article 2118.