Was tithing only for israelites who *worked* in agriculture and livestock?

The tithing requirement was given to only this nation. The nation of Israel was as a agricultural nation which raised crops & livestock. After establishing themselves centuries later in Israel after coming under Roman rulership, some abandoned tithing which lead to the tribe of Levi, the priesthood to suffer because they relied on such tithings to support them (Nu 18:20-21) due to the fact that they had no inheritance of the land for their life's service was to oversee the spiritual needs of all 12 tribes continually. FOOT NOTE: If a person wished to buy back their livestock & the produce of the land they could in turn pay a 10% plus 5%. Le 27:30-31