Whoever separates from the community and degrades the authority will meet Allah with no argument in his favour

It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that he said: I heard the Messenger of Allah (peace and blessings be upon him) saying: "Whoever separates from his Ummah (its Jama'ah), or returns to being a Bedouin (the nomadic desert life) after his Hijrah, will have no excuse (proof) (on the Day of Resurrection)."
The two Shaykhs have recorded a similar hadith from Abu Hurayrah (may Allah be pleased with him): "Whoever separates from the Jama'ah and dies, dies a death of Jahiliyyah," but this text is different from that one. The sixth hadith indicating that consensus is a proof is as follows.

It is narrated from Rib'i bin Hirash that he said: I came to Sayyiduna Hudhayfah bin al-Yaman (may Allah be pleased with him) in the days when the people had set out against Sayyiduna Uthman (may Allah be pleased with him) (to rebel against him), and he said: I heard the Messenger of Allah (peace and blessings be upon him) saying: "Whoever separates from the Jama'ah and holds authority (government, the order of the state) in contempt will meet Allah having no proof (in his defence)."
Abu Asim corroborated it from Kathir.

It is narrated from Rib'i bin Hirash that he came to visit Sayyiduna Hudhayfah bin al-Yaman (may Allah be pleased with him) (Hudhayfah's sister was married to Rib'i). Hudhayfah (may Allah be pleased with him) asked: O Rib'i, what have your people done? (This was the time when the people had gone out against Sayyiduna Uthman (may Allah be pleased with him).) Rib'i said: Some of them have gone out, and he named a few of them. Hudhayfah (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him) saying: "Whoever separates from the Jama'ah and holds authority in contempt will be presented before Allah in such a state that no proof of his will be accepted with Allah."
This hadith is sahih; Kathir bin Abi Kathir is trustworthy and there is no criticism against him.

It is narrated from Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "There are three kinds of people about whom you should not ask me (because of their ruin, i.e. they are among the ruined): a man who separated from the Jama'ah, disobeyed his Imam and died in that state of disobedience; a slave, male or female, who ran away from his master and died in that state; and a woman whose husband is absent (on a journey) and has fully provided for her worldly expenses, yet in his absence she displays her adornment (before other men). So do not ask about them."
This hadith is sahih on the condition of the two Shaykhs; all its narrators are ones they used as evidence, but they did not record it, and there is no hidden defect ('illah) in it.