Isaiah 18:5
For afore the harvest, when the bud is perfect, and the sour grape is ripening in the flower, he shall both cut off the sprigs with pruning hooks, and take away and cut down the branches. For afore the harvest, when the bud is perfect, and the sour grape is ripening in the flower, he shall both cut off the sprigs with pruning hooks, and take away and cut down the branches.
Isaiah 18 concerns the southern part of Africa. Those who understand the chapter otherwise take it to refer to the New World. The cutting off of sprigs and branches before the harvest is the cutting away of the wicked, worthless branches. The final warning message goes out before the harvest so described. The cutting takes place when the plagues come, which continue for a year through summer and winter. After the cutting, God's children are gathered home.