I am a hundred twenty years old, and I am no longer able to be your leader. And besides that, the LORD your God has told me that he won't let me cross the Jordan River.
But Abishai came to the rescue and killed the Philistine. David's soldiers told him, "We can't let you risk your life in battle anymore! You give light to our nation, and we want that flame to keep burning."
We can expect seventy years, or maybe eighty, if we are healthy, but even our best years bring trouble and sorrow. Suddenly our time is up, and we disappear.
But the LORD said to Moses and Aaron, "Because you refused to believe in my power, these people did not respect me. And so, you will not be the ones to lead them into the land I have promised."