Have you called them to islam?
 

He saw the newly brought captives to Medina... And he asked His friends, who took them captive:

-“Have you called them to Islam?”

When he got the answer "No!", he also asked the captives in order to clarify the situation:

-Have you been called to the Islam?

When he got the answer "No!" from them, he gave an order and the captives were released; then, they returned to their countries.