I'm not quarreling with anyone's decision to tithe no matter what their compulsion to do so. I'm quarrelling with an assertion that it's a sin NOT to tithe for those who do not feel so led by the Holy Spirit. That this is a false statement of doctrine is not a disputible matter. It was the original poster who asserted the false imperative and pointing it out is not quarrelling with him over his personal choice to do so if he desires.
Yes, I thought you were.
"That this is a false statement of doctrine is not a disputible matter."
So the Scripture against quarreling with what a weaker brother doesn't apply if you define it as a false statement of doctrine rather than a disputable matter? Isn't that exactly what Paul was dealing with in Rom 14?
"It was the original poster who asserted the false imperative and pointing it out is not quarrelling with him over his personal choice to do so if he desires."
You said, "...we shouldn’t lie to other Christians" and "I am still waiting...". That looks like more than just 'pointing it out'.
It is clear that it is only your opinion that it was a false imperative. It appears that your position rests entirely on your understanding of Christ's reference to fulfilling the law. Your brother has a different understanding of Christ's reference to fulfilling the law, that's all.
Now if he had said you must tithe to be saved, then you would have a valid doctrinal point.
But he didn't and you don't.