Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "Whenever some people sit together in a place and do not remember Allah there, nor do they send blessings upon the Prophet (peace and blessings be upon him), then this will be a cause of regret for them on the Day of Resurrection, even if those people enter Paradise."
Hadith Referenceصحیح ابن حبان / كتاب البر والإحسان / 592
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - وهو مكرر ما قبله.فضيلة الشيخ العلّامة شُعيب الأرناؤوطهو مكرر ما قبله.