He has already fulfilled it—namely His words: “Say to those captives who are in your hands: If Allah knows any good in your hearts, He will grant you better than what was taken from you, and He will forgive you” (al-Anfāl 8:70).
“This,” al-ʿAbbās said, “is better than what was taken from me, but I do not know what will be done in the Hereafter.” (1)

Abu al-Zinād narrated through al-Aʿraj from Abū Hurayrah:
“The Messenger of Allah ﷺ sent ʿUmar to collect the alms-tax. Ibn Jamīl, Khālid, and al-ʿAbbās withheld payment. The Messenger of Allah ﷺ commented: ‘What grievance does Ibn Jamīl have except that he was poor and Allah enriched him? As for Khālid, you are treating him unjustly; he has set aside his armor and mounts for the cause of Allah. As for al-ʿAbbās, his zakat is my responsibility—and an equal amount besides.’
He then said, ‘Do you not realize that a man’s paternal uncle stands in the place of his father?’ (2)

Al-Aʿmash narrated, from ʿAmr ibn Murrah, from Abū al-Bakhtari, from ʿAlī, who said:
“I said to ʿUmar, ‘Do you not remember when you complained about al-ʿAbbās to the Messenger of Allah ﷺ, and he replied, “Do you not know that a man’s paternal uncle stands in the place of his father?”’ (3)”

Ḥusayn ibn ʿAbd Allāh ibn Ḍumayrah related, from his father, from his grandfather, from ʿAlī, that