Genesis 28

Malachi revealed the commandment and the promise to those who obey the law of tithing -

"Bring ye all the tithes into the storehouse, that there may be meat in mine house, and prove me now herewith, saith the LORD of hosts, if I will not open you the windows of heaven, and pour you out a blessing, that there shall not be room enough to receive it.
11 And I will rebuke the devourer for your sakes, and he shall not destroy the fruits of your ground; neither shall your vine cast her fruit before the time in the field, saith the LORD of hosts.
12 And all nations shall call you blessed: for ye shall be a delightsome land, saith the LORD of hosts." (Old Testament | Malachi 3:10 - 12)

It is apparent that this commandment and promise was apparent in the days of Abraham and Jacob. The Lord gave great promises to Abraham, so to Melchizedek, Abraham -

"...gave him tithes of all." (Old Testament | Genesis 14:20)

After great promises were given to Jacob, he responded -

"...and of all that thou shalt give me I will surely give the tenth unto thee." (Old Testament | Genesis 28:22)

It becomes apparent that this commandment has been from the beginning. I wonder why few religions teach this great commandment.