John 4:38

I sent you to reap,.... To preach the Gospel, and gather in souls by your ministry; referring to the mission of them in

Matthew 10:6;

that whereon ye bestowed no labour; being sent to the Jews, who had the writings of the prophets, and were versed in them; and had learned from them that the Messiah was to come, and were now in general expectation of him; so that they had nothing more to do, than to declare to those persons who were cultivated by the prophets, and were like to ground tilled and manured, that the Messiah was come, and the kingdom of heaven was at hand.

Other men laboured; the prophets, and John the Baptist:

and ye are entered into their labours; to finish the work they had begun, and which was almost done to their hands.