Pay attention, you who say, "Today or tomorrow we will go to such-and-such a town. We will stay there a year, buying and selling, and making a profit."
You don't really know about tomorrow. What is your life? You are a mist that appears for only a short while before it vanishes.
Here's what you ought to say: "If the Lord wills, we will live and do this or that."
But now you boast and brag, and all such boasting is evil.
It is a sin when someone knows the right thing to do and doesn't do it.