It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: When some people gather at a place and disperse without remembering Allah, it is as if they dispersed from the carcass of a dead donkey, and that gathering will be a cause of regret for them on the Day of Resurrection.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 10680