Theophylact of Ohrid
Catena Aurea · Johannesevangelium 4
Say not ye, There are yet four months, and then cometh harvest? behold, I say unto you, Lift up your eyes, and look on the fields; for they are white already to harvest. And he that reapeth receiveth wages, and gathereth fruit unto life eternal: that both he that soweth and he that reapeth may rejoice together. And herein is that saving true, One soweth, and another reapeth. I sent you to reap that whereon ye bestowed no labour: other men laboured, and ye are entered into their labours.
Now ye are expecting a material harvest. But I say unto you, that a spiritual harvest is at hand: Lift up your eyes, and look on the fields; for they are white already to harvest. He alludes to the Samaritans who are approaching.