Hadees Related to Dawah (Dawat-o-Tableegh)

Muhammad ibne-'Uthman ibne-Haushab narrates from his grandfather Radiyallahu 'anhu that when Allah blessed Muhammad with supremacy, I sent to him a group of forty riders under 'Abde Sharr. They reached him with my letter. Rasulullah Sallallahu 'alaihi wasallam asked him: What is your name? He replied: 'Abdu Sharr (slave of evil). Rasulullah said: No, but you are 'Abdu Khair (slave of good). Rasulullah Sallallahu 'alaihi wasallam took his oath of allegiance in Islam and sent the reply of the letter to Hawshab Zee Zulaim through him. So Hawshab accepted Islam. (Isabah)