God eliminates usury, and increases charity; and God loves not every ingrate and sinner.
(2:276)
It might seem counterintutive since we are subjected day and night to the idea that we need to hoard wealth and not spend it. But, God says in the Qur'an that He blesses (increases) charity and eliminates usury. Therefore, if you wish abundance then you must give in charity.
If you reveal charity, excellent is it; but if you hide it, and give it to the poor, it is better for you, and He will remove from you some of your evil deeds; and God is aware of what you do.
(2:271)
Giving in charity, especially in secret, has the added benefit of removing from you your sins.
Charity is but for the poor and the needy, and the workers with it, and those whose hearts are to be reconciled, and for slaves and debtors, and in the cause of God, and the wayfarer — an obligation from God; and God is knowing and wise.
(9:60)
They ask thee what they should spend. Say thou: “Whatever you spend of good for parents and relatives, and the fatherless, and the needy, and the wayfarer,[...]. And whatever you do of good, God knows it.”
(2:215)
God, Himself, is teaching us how we can increase in wealth and abundance. And of course, the following verses bears constant remembering:
The likeness of those who spend their wealth in the cause of God is as the likeness of a grain which grows seven ears, in each ear a hundred grains. And God increases manifold to whom He wills; and God is encompassing and knowing.
Those who spend their wealth in the cause of God, then follow not what they have spent with condescension or hindrance, they have their reward with their Lord; and no fear will be upon them, nor will they grieve.
Fitting speech and blindness to deficiency are better than charity followed by hindrance; and God is free from need and clement.
O you who heed warning: make not your charity vain through condescension and hindrance, like one who spends his wealth to be seen of men and believes not in God and the Last Day. And his likeness is as the likeness of a rock whereon is dust: a downpour fell upon it leaving it bare; they possess nothing from what they have earned; and God guides not the people of the false claimers of guidance.
And the likeness of those who spend their wealth seeking the pleasure of God and as a confirmation of their souls, is as the likeness of a garden on high ground: a downpour fell upon it, and it yielded double fruit; and if a downpour falls not upon it, then fine rain; and God sees what you do.
Would one of you wish to have a garden of date-palms and grapevines, beneath which rivers flow, he having every fruit therein?[...]. And old age befell him, and he had weak progeny, and a cyclone wherein was fire befell it, and it was burned up. Thus does God make plain to you the proofs, that you might give thought.
O you who heed warning: spend of the good things you have earned, and of what We have brought forth for you from the earth. And resort not to the bad thereof, to spend thereof, when you would not take it save you closed an eye to it; and know that God is free from need and praiseworthy.
The satan promises you poverty, and enjoins upon you sexual immorality, but God promises you forgiveness and bounty from Him; and God is encompassing and knowing.
He gives wisdom to whom He wills; and to whom wisdom is given, he has been given much good; but only those of insight take heed.
And what you spend of an expenditure or make of a pledge, God knows it. And there are for the wrongdoers no helpers.
(2:261-270)