I must commend those who have challenged this teaching. The person(s) responsible for this 10% plus 5% are the ones about whom it is written, "Neither give heed to fables and endless genealogies , which minister questions, rather than godly edifying which is in faith : so do. Now the end of the commandment is charity [love] out of a pure heart, and of a good conscience, and of faith unfeigned: From which some having swerved have turned aside unto vain jangling ;(having…: or, not aiming at)
Desiring to be teachers of the law; understanding neither what they say, nor whereof they affirm. But we know that the law is good , if a man use it lawfully; ..."
The attempt to make merchandise of the saints, by manipulating both the content and the context of this passage (
Ex 30:13-15), is a classic case of scripture being twisted to "support" some man-made agenda. Or, the preachers who teach the 10 + 5 doctrine are simply ignorant of the Hebrew history, religion, and language and have joined the ranks of the blind teachers attempting to make blind followers.
Again, those who have challenged this precept, thank you and God's grace be unto you.