The scriptures sometimes use the word harvest figuratively to refer to bringing people into the Church, which is the kingdom of God on the earth, or to a time of judgment, such as the second coming of Jesus Christ.
The harvest is past, the summer is ended, and we are not saved, Jer. 8: 20 (D&C 56: 16). The harvest is great, but the laborers are few, Matt. 9: 37. The harvest is the end of the world, Matt. 13: 39. Whatsoever a man soweth, that shall he also reap, Gal. 6: 7-9 (D&C 6: 33). The field is white already to harvest, D&C 4: 4. The harvest is ended and your souls are not saved, D&C 45: 2. The time of harvest is come, and my word must be fulfilled, D&C 101: 64.