In ancient times the tithe was a requirement of the Law and tied to giving a certain percentage of earnings, crops, livestock etc. that was given to the temple.
Some people struggle with the concept but this description found on the internet should help provide an understanding of this spirit of giving and serving.
The New Testament talks about the importance and benefits of giving. We are to give as we are able. Sometimes that means giving more than 10 percent; sometimes that may mean giving less. It all depends on the ability of the person and the needs of the community and their surroundings. Everyone should diligently pray and seek God’s wisdom in the matter of participating in tithing and/or how much to give (James 1:5). ABOVE ALL, ALL TITHES AND OFFERINGS SHOULD BE GIVEN WITH PURE MOTIVES AND AN ATTITUDE OF THANKS AND SERVICE TO THE GREATER GOOD. “Each man should give what he has decided in his heart to give, not reluctantly or under compulsion, for God loves a cheerful giver” (2 Corinthians 9:7).