From the Benefits of the Sittings of Knowledge

Upon the authority of Sahl ibn Handhalah رضي اللّه عنـه who said: “The Messenger of Allaah صلّى اللَّهُ عليه وسلّم said:

“A people do not sit together remembering Allaah and then rise from their place of sitting, except that it is said to them: "Rise! For indeed Allaah has forgiven your sins and has turned your evil deeds into good ones!”

{Collected by At Tabaraani & declared ‘Saheeh’ by Shaikh Albaani رحمه الله in ‘Saheehul Jaami’ (5610)}