Come now, you who say, "Today or tomorrow we will go to
such and such a city, and spend a year there and engage in business
and make a profit." 14 Yet you do not know what your life will be
like tomorrow. You are just a vapor that appears for a little while
and then vanishes away. 15 Instead, you ought to say, "If the Lord
wills, we will live and also do this or that." 16 But as it is, you
boast in your arrogance; all such boasting is evil.

Education for Exultation - Beginning and Ending with God