It is narrated from Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Any people who gather in a sitting and then disperse without remembering Allah, that sitting will be a cause of regret for them on the Day of Resurrection."
Imam al-Tabarani (may Allah have mercy on him) said: "This hadith is narrated from Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him) only through this chain; Shaddad bin Sa'id is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب العين / 3744
Hadith Gradingمحدثین:رجاله رجال الصحيح
Hadith Takhrij«قال الهيثمي: رجاله رجال الصحيح «مجمع الزوائد ومنبع الفوائد، ج 10، ص 80»» «أخرجه ابن حجر فى «المطالب العالية» برقم: 3416»