Ali's hand of Justice

Abu ‘Ali al-Hasan ibn Abdillah al-Qattan, reported to me from Abu Amru Uthman ibn Ahmad, popularly known as Ibn al-Sammak, who reported from Abu Bakr Ahmed ibn Muhammad ibn Swaleh al-Tammar, who reported from Muhammad ibn Muslim al-Razi, who reported from Abdullah ibn Raja, who reported from Israeel, from Abu Ishaq, from Habshi ibn Junadah, who said:
I was once sitting with Abu Bakr, when a man came to him and said: "O Caliph of the messenger of Allah, the Prophet, peace be upon him and his progeny, had promised to scrimp to me three measures of dates." So Abu Bakr said: "Call ‘Ali for me." ‘Ali, peace be upon him, came, and Abu Bakr told him: "O Abul Hasan, this man says that the Prophet, peace be upon him and his progeny, had promised to scrimp him three measures of dates, so give them to him."
He gave him three measures of dates. Then Abu Bakr said: "Count them." They found out that each measure contained sixty dates. So Abu Bakr said: "The messenger of Allah spoke the truth. On the night of Hijrah (i.e. migration) I heard the Prophet as we were on our way from Makkah to Madinah saying: O Abu Bakr, my palm and ‘Ali's palm are equal to each other in justice."