❝ HadithA party of horsemen captured Thumamah ibn Uthal, chief of al-Yamamah, and tied him to a pillar of the Prophet's Mosque. For three days the Messenger of Allah ﷺ went to him and asked: what do you have, Thumamah? He said: if you kill, you kill one whose blood will be avenged; if you show favour, you show it to a grateful man; and if you want wealth, ask what you will. On the third day the Messenger of Allah ﷺ said: release Thumamah. Freed, Thumamah went to a nearby palm grove, bathed, came back into the mosque and bore witness. He said: O Muhammad, by Allah, there was no face on earth more hateful to me than yours, and now yours is the dearest of all faces to me. There was no religion more hateful to me than yours, and now it is the dearest to me.Sahih al-Bukhari 4372 · Sahih
In three days as a captive he had seen the life of the mosque — the prayer, the Quran, the Companions' conduct, and the kindness shown to him. Release without conditions opened the door of his heart.