Ma'seris the Hebrew word for tithe, literally meaning a tenth is a tenth of all your income, livestock, fruit of the tree and all. 

Tithe from the onset is not yours but belongs to God so you should not even budget for yourself before putting away the tithe. It is the first thing on your budget(Leviticus 27:30-32). Tithing is taking 10% of all your income back to God by presenting it in His House, the Church.

(Most Info from Propet B. Chiza, The Blessing Connector.)
Tithing is not a burden and it is not doing God a favour because God owns everything and everything that you have was initially given you and can be taken back by Him. God does not become "more God" because you have tithed but you become blessed because of tithing.

Not tithing is tantamount to robbing God and brings a curse on your life. A robber is a person who despoils another of property or belongings by violence, feloniously plunder, depriving what is due to another person. A curse is the empowerment to fail. you can read Malachi 3:8-12. Which robber is better, the one who robs banks and the one robbing an invisible, Almighty being?
What is a tithe?
If you tithe God promises to open the floodgates of Heaven and when you give He pours out a mighty blessing on you. A blessing is the empowerment to prosper. Tithe opens the floodgates of Heaven, offerings provoke pouring of a blessing. the two must always be together to work properly. after this provide God a work He can bless then watch and see what the Lord will do.
Many people who do not tithe never know where their money is going. They try business exploits and they fail, they try other things and fail, their marriages are unhappy, their lives sad, their families constantly sick, they end up witch-hunting or blaming other people for their woes.

My prayer is you fully understand the blessing, not burden, of tithing and henceforth live a life of tithing and blessing. If you do not start this Sunday you will never do. I will never be poor again, I am a tither, I am a giver, I am a worker!