It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) said: "Whoever dies having separated from the Jama'ah (the community) dies a death of Jahiliyyah (pre-Islamic ignorance)."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13221
Muslim bin Jundub (may Allah have mercy on him) narrates that he went with Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) to visit Ibn Muti'. He (Ibn Umar) said: "Al-salamu alaykum." He (Ibn Muti') said: "Wa alaykum al-salam wa rahmatullah. Welcome, O Abu Abd al-Rahman! Place a cushion for him." Ibn Umar (may Allah be pleased with them both) said: "Had I not heard the Messenger of Allah (peace and blessings be upon him) say that three things are not to be refused: milk, a cushion and oil, I would not have sat on it."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13222