Sahih Muslim 1493 f
Translation
Sa'id b. Jubair reported that Mus'ab b. Zubair did not effect separation between the Mutala'inain (invokers of curses). Sa'id said
It was mentioned to 'Abdullah b. Umar (Allah be pleased with them) and he said: Allah's Apostle (ﷺ) effected separation between the two members of Banu al-'Ajlan.