Tithing has been used since the times of the early Egyptians, Babylonians, Arabians, Greeks, Romans, and Chinese. The word "tithe" means "tenth" and the ancient people regarded (the number) 10 as the number representing increase.
The foundation for the ancient law of prosperity is the universal belief that true prosperity comes from a spiritual basis. God, Buddha Nature or Absolute Awareness is the Source of all supply. Our minds, emotions, bodies, our talents, education, experiences, our jobs or professions are all vehicles or instruments of this prosperity; however Spirit or Awareness is the source. It therefore follows that if we want to be consistently prosperous we need to do something to "keep in touch" with that infinite source of all supply.
True Generosity is the practice of selfless giving (ie with no strings attached). It is also known by the universal adage "as you give so shall you receive." Regular, consistent giving opens the door to regular, consistent receiving. This must be done in a specific manner; through the giving of the "tith"” or a "tenth" portion of your income firstly to wherever you are receiving spiritual guidance or inspiration, on a regular monthly basis. You will prosper, and you will also help your spiritual teacher or organization to continue with their spiritual mission of helping mankind. From there - everyone prospers. It is important to emphasize that one's intention need to be on selfless-giving, and not on the getting.
Kahlil Gibran wrote in the Prophet, "It is good to give when asked, but it is better to give when unasked, through understanding."
Tithing is an act of faith which functions on spiritual principles in order to protect and bless the "tither". Many people think, "but I can’t afford to tithe" or "I don’t have enough to tithe." These examples of limiting thoughts are part of the reasons why one doesn’t have enough. They contribute to the self -fulfilling prophecy that you’ll never have enough. It sometimes requires a "leap of faith" to overcome these resistant thoughts and allow spiritual abundance, prosperity and well-being into our lives.