29 Thou shalt not delay to offer the first of thy ripe fruits, and of thy liquors: the firstborn of thy sons shalt thou give unto me.
30 Likewise shalt thou do with thine oxen, and with thy sheep: seven days it shall be with his dam; on the eighth day thou shalt give it me.
The first of all you create, make or produce belongs to God. After all, had He not given you the means with which to obtain it, you would not have it. Therefore, you honor God by offering it back to him.
As a taxi driver/courier, I struggled with how I am supposed to do this. What do I produce? And, the only thing I can come up with is money.
Therefore, the very first trip I make from here on out goes into my "God account" to be invested until such time as the Good Lord tells me I need it to help someone in need that He calls me to give to.
For you, it might be the first meal you serve, the first tip you make, the first hour of pay you receive for the week...
This verse clearly states that the first of it belongs to the Lord.