G-d instructed us to bring a tenth of what we have and bring it to the Temple. This is for G-d’s use.
This is called charity.
G-d is the one who provides all wealth. Not us. G-d gives us the ability to earn a living thus when we give a tithe to G-d’s house we are in fact showing G-d how much we honour HIM and follow HIS ways for us to live.
I do it because I want to please and give Honour to my father.
“Moses then taught the Jewish people that after they settle the Land of Israel and begin working the land, G‑d has obligated them to bring a tenth of their oil, wine, and grain to the Temple-city and consume it there. This ensured that the people would regularly visit Jerusalem (which was chosen to be the Temple-city) in order to renew their spiritual inspiration.
[Moses told the Jewish people,] “You must tithe all the produce of the seed that the field yields year by year.” Deuteronomy 14:22
This verse includes the instruction to donate a portion of our income to charity. The Talmudic sages pointed out that the similarity of the Hebrew words for “tithe” (ta’aseir) and “become rich” (titasheir) alludes to the fact that G‑d rewards those who give charity with abundant wealth.
Furthermore, when we resolve to give charity beyond our means, G‑d grants us the wealth that is required in order for us to give the charity we have resolved to donate.1 Igrot Kodesh, vol. 14, p. 211