Musab did not separate the Mutalaineen.Saeed said, "This was mentioned to Ibn Umar, and he replied, 'The Messenger of Allah ﷺ separated the two siblings of the Ajlan clan.'"
لم يفرق المصعب بين المتلاعنين قال سعيد: ذكر ذلك لابن عمر فقال: فرق رسول الله ﷺ بين أخوي العجلان.
Muslim narrated it in the chapter on mutual imprecation (7:1493), and Nasai (3474), both from the hadith of Muhammad bin Muthanna, and the wording is his. They said, Muaz bin Hisham told us, my father told me, from Qatada, from Azra, from Saeed bin Jubayr, and he related it.Its apparent meaning is that the mutual imprecation must take place before the judge, and the separation occurs through his separating the couple, because of the other rulings that follow from it, such as the punishment for false accusation, if the man names the man accused of adultery and presses the claim against him.As for when he does not press the claim, he is not punished. Likewise, the one accused is not punished merely for the accusation itself, for it is not established that Sharik bin Sahmaa was punished, just as it is not established that he pressed for the punishment of the accuser, who was Hilal bin Umaya, but had he pressed for it, the accuser would have been punished.