Shaykh Tabarsi etc. have narrated through authentic chains of narrators from Imam Ja’far Sadiq (a.s.) that one day Najjashi called Ja’far with his companions and when they came, they saw that Najjashi was seated on the ground wearing old clothes. Ja’far says: When we saw this, we were shocked and when he noticed our apprehension, he said: “I thank the Almighty Allah who helped Muhammad and lighted my eyes with his help.
Would you like to hear the good news? “Yes,” I said. He said: “Right now my spy has told me that the Almighty Allah helped his Prophet and killed many of his enemies. So and so was killed and so and so were taken captive. Their battle took place in a valley called Badr. As if I can see that valley in which I used to graze the sheep of my master which was situated in Bani Zumra.”
Ja’far asked: “O good king, why are you seated on the ground and why have you donned old clothes?” He replied: “O Ja’far, we have read in Injeel that when the Almighty Allah, the generous one, bestows some favor to the servant, the servant is duty bound to offer thanks at that moment and it is mentioned in that same Injeel that in the view of Allah no thankfulness is better than humility. Thus I have adopted this humility to thank for the victory of the Prophet.”
When the Messenger of Allah (S) heard this he said to his companions: “Sadaqah increases the wealth of the giver, so you must also pay Sadaqah so that the Almighty Allah is more merciful to you humility results in honor, so you must also adopt humility; so that the Almighty Allah also raises your grades and forgiveness increases respect. So forgive the mistakes of others so that the Almighty Allah may hold you respectable.