Offering our Tithe (10% of our finances) and Time to God is a practical recognition that He, and not we is in charge of our lives. 

Bring the whole tithe into the storehouse, that there may be food in my house. Test me in this,” says the Lord Almighty, “and see if I will not throw open the floodgates of heaven and pour out so much blessing that there will not be room enough to store it. 
Malachi 3:10

“Each tithe was in recognition that man owed all he had to the God who had given from His bounty. Even the calling of the elected Hebrew people was symbolic that all men belong to God. They were not set apart for their own privilege, but to be ‘a light to the nations’.” 

R. Turnbull

Dan is talking about Tithing: