The same sura 9 ( At-tawba ) teachs us :

((( And if any one of the polytheists seeks your protection,then grant him protection so that he may hear the words of Allah. Then deliver him to his place of safety. That is because they are a people who do not know. )))




The commentary ( Tafsir) :

Quote
"lf during a fight, an enemy makes a request that he should be given an opportunity to understand Islam, the Muslims should give him a surety of protection and allow him to visit them. They should then present Islam before him in order to make him understand it. If, after this, he dces not embrace Islam, they should convey him safely to his place" . Such a person who comes to Dar-ul-Islam under the above mentioned protection is called musta'min in the Islamic Code.