Read this:
"You shall truly tithe all the increase of your grain that the field produces year by year. And you shall eat before the Lord your God, in the place where He chooses to make His name abide, the tithe of your grain and your new wine and your oil, of the firstborn of your herds and your flocks, that you may learn to fear the Lord your God always. But if the journey is too long for you, so that you are not able to carry the tithe, or if the place where the Lord your God chooses to put His name is too far from you, when the Lord your God has blessed you, then you shall exchange it for money, take the money in your hand, and go to the place which the Lord your God chooses. And you shall spend that money for whatever your heart desires: for oxen or sheep, for wine or similar drink, for whatever your heart desires; you shall eat there before the Lord your God, and you shall rejoice, you and your household. You shall not forsake the Levite who is within your gates, for he has no part nor inheritance with you." Deut 14:22-27
If you had an understanding of the biblical Feasts of the Lord, you would understand that this ‘tithe’ or tenth - was to be SAVED all year for the purpose of keeping the Feast of Tabernacles, the 6th commanded ANNUAL festival (Leviticus 23). A tithe was to be saved in ADDITION to the tithe used for the Priesthood (or Lord’s work), and that 2nd Tithe was to be spent in celebration of the Feast of Tabernacles, on whatever your heart desired.
Since the church today essentially is in ignorance of the biblical Feasts of the Lord, it is not surprising many have no understanding of how this second tithe was used. Yes, it was essentially a command from the Almighty that “during My Feast of Tabernacles, you are commanded to party before Me”. That savings of the tithe was to ensure each family had the means and ability to attend and enjoy the 8 day festival.
There was also ANOTHER tithe to be taken in Ancient Israel. A third tithe every third year wherein those funds were to be shared with the poor and the orphans (Deuteronomy 14:28-29).
The OP of this thread was asking about the First Tithe that was to be sent to the Levitical Priesthood and for the work of the Lord.