Proverbs 27:1 (NIV)
27 Do not boast about tomorrow, for you do not know what a day may bring.

Boast not thyself, no, not of to-morrow, much less of many days or years to come. This does not forbid preparing for to-morrow, but presuming upon to-morrow. We must not promise ourselves the continuance of our lives and comforts till to-morrow, but speak of it with submission to the will of God and as those who with good reason are kept at uncertainty about it. [Matthew Henry]

The hymn-writer wrote, "Change and decay in all around I see." Change and decay are enemies that most people fear. ... When we are young, change is a treat; but as we grow older, change becomes a threat. But when Jesus Christ is in control of your life, you need never fear change or decay. ... When you are part of eternity, the decay of the material only hastens the perfecting of the spiritual, if you walk by faith in Christ. [Warren W. Wiersbe, His Name Is Wonderful. Christianity Today, Vol. 30, no. 2.]

Paul McCartney once said, �Close your eyes and I�ll kiss you, Tomorrow I�ll miss you.