Luke 16:10-17 begins with the statement about the small things reflecting the large. And it could easily have gone the direction of so you must tithe the mind, the dill and the other small things, but instead goes to the whole question of how we use our riches and our gifts. It is not about being persnickety, but about whom we serve.
I serve a God who claims to be the Way, the Truth and the Life. And following a God who makes that claim means that we should seek to be truthful and faithful. And so being faithful in the small things indicates where we will be in the large. And so working to be honest about the things where the truth won't harm anyone and only inconvenience us is about following the one who says he is the Truth. And the little things reflect our services both large and small to the one we claim to worship.
Luke 16:10-17 (18)
 "Whoever is faithful in a very little is faithful also in much; and whoever is dishonest in a very little is dishonest also in much.
 If then you have not been faithful with the dishonest wealth, who will entrust to you the true riches?  And if you have not been faithful with what belongs to another, who will give you what is your own?  No slave can serve two masters; for a slave will either hate the one and love the other, or be devoted to the one and despise the other. You cannot serve God and wealth."
 The Pharisees, who were lovers of money, heard all this, and they ridiculed him.  So he said to them, "You are those who justify yourselves in the sight of others; but God knows your hearts; for what is prized by human beings is an abomination in the sight of God.
 "The law and the prophets were in effect until John came; since then the good news of the kingdom of God is proclaimed, and everyone tries to enter it by force.  But it is easier for heaven and earth to pass away, than for one stroke of a letter in the law to be dropped.
 "Anyone who divorces his wife and marries another commits adultery, and whoever marries a woman divorced from her husband commits adultery.