A parable is a form of communication, a dialogue between a narrator and listener
I had this story from one who had no business to tell it to me, or to any other. I may credit the seductive influence of an old vintage upon the narrator for the beginning of it, and my own skeptical incredulity during the days that followed for the balance of the strange tale.Edgar Rice Burroughs
The Apostle of Allah (peace_be_upon_him) said on the day of Badr: He who kills a man will get such-and-such, and he who captivates a man will get such-and-such. The narrator then transmitted the rest of the tradition in a similar manner. The tradition of Khalid is more perfect.
When it was the day (of the battle) of Badr, prisoners of war were brought including Al-Abbas who was undressed. [ Muhammad ] looked for a shirt for him. It was found that the shirt of 'Abdullah bin Ubai would do, so the Prophet let him wear it. That was the reason why the Prophet took off and gave his own shirt to 'Abdullah. (The narrator adds, "He had done the Prophet some favor for which the Prophet liked to reward him.")