It is reported that the Messenger of Allah  said: "Whoever sat a session in which he made no mention of Allah The Exalted, there was upon him a tirah", meaning a shortcoming, and a thing to regret.

Reporters.
Reported by Abu Dawood. Al-Albani said it was sound (saheeh), and he said that Abu Dawood's ascription was comely (isnaduhu hasan); however, it has many other channels of ascription, some of which are sound according to the conditions of Imam Muslim. Al-Albani included this hadeeth in The Authentic of Good Sayings as #5.