Before the advent of today’s harvesting technology, the sickle was used to harvest a ripe crop (specifically grain, be it barley, wheat, flax, etc.). As the sickle was swung in a stand of grain, the stalks, severed from their roots, fell horizontally to the ground and could be gathered for threshing. Before the harvest began, the farmer would take time to sharpen the cutting edge of his sickle for greater efficiency. That Christ Jesus has a sharp sickle in his hand indicates that he is ready to begin harvesting.
14 Then I looked, and behold, a white cloud, and seated on the cloud one like a son of man, with a golden crown on his head, and a sharp sickle in his hand.