Ruling on one whose only intention in giving charity and zakah is to increase his wealth
Question

Some people say: I only give zakah on my wealth and charity for the purpose of increasing this wealth and getting blessing (barakah) in it. What do you advise?
Praise be to Allah.There is nothing wrong with that, and Allah pointed out something like that, as He tells us that Nooh (peace be upon him) said to his people (interpretation of the meaning):
{And said, 'Ask forgiveness of your Lord. Indeed, He is ever a Perpetual Forgiver.
He will send [rain from] the sky upon you in [continuing] showers} [Nooh 71:10-11].
The Prophet (blessings and peace of Allah be upon him): “Wealth never decreases because of giving charity.” And he (blessings and peace of Allah be upon him) said: “Whoever would like to have a long life and ample provision, let him uphold his ties of kinship.” Allah, may He be glorified and exalted, only ordained these worldly benefits in order to encourage people, and if they are encouraged by these promises, then they will do these things. But the one who seeks the hereafter will attain benefits both in this world and the hereafter, as Allah, may He be exalted, says (interpretation of the meaning):
{Whoever desires the harvest of the Hereafter - We increase for him in his harvest} [ash-Shoora 42:20].
That is, We will give him benefits in both this world and the hereafter. As for seeking only worldly benefits when doing acts of worship, undoubtedly this is a shortcoming in one’s intention, the cause of which is excessive focus on and love of this world in the heart of the one who does that. End quote.
Shaykh Muhammad ibn ‘Uthaymeen (may Allah have mercy on him).
Liqaa’aat al-Baab al-Maftooh (3/505).