Da'wah - Calling To Islam The Salaf - Pious Predecessors

Our Salaf: Imaam Ahmad–Five Thousand or more attented his gatherings and what did they learn?

Imaam Dhahabi (rahimahullaah) reported in Siyar A’laam Nubulaa: [10/216]

There used to be roughly five thousand or more in the gatherings of Imaam Ahmad (rahimahullaah).  Five hundred used to write and the rest would learn good manners and good character from him.