Allah the Exalted says:
“Say: In the bounty of Allah and in His mercy: therein let them rejoice. It is better than what they hoard.” (10:58)
Ibn 'Abbas, may Allah be pleased with them both, said:
The bounty of Allah is the Qur'an, and His mercy is Islam.
That is, through this guidance and the true religion that has come to them from Allah.
"Let them rejoice in it," for it is the most worthy thing for them to rejoice over.
“Say: In the bounty of Allah and in His mercy: therein let them rejoice. It is better than what they hoard.” (10:58)
That is, as opposed to the fleeting debris of this world and all that it contains.
From the transient, vanishing splendor that will inevitably pass away.
Ibn Abi Hatim recorded in his Tafsir of this verse:
When the tribute from Iraq was brought to 'Umar, may Allah be pleased with him,
'Umar went out with a freedman of his.
'Umar began to count the camels.
And they were even more than that.
'Umar began to say:
"Praise be to Allah the Exalted."
And the freedman said:
"By Allah, this is from the bounty of Allah and His mercy."
'Umar replied:
"You have lied."
"This is not what Allah the Exalted is referring to."
“Say: In the bounty of Allah and in His mercy: therein let them rejoice. It is better than what they hoard.” (10:58)
“Say: In the bounty of Allah and in His mercy: therein let them rejoice. It is better than what they hoard.” (10:58)
And this is among the things they gather.