John the Apostle
John 4:38ESV·traditional attribution

I sent you to reap that for which you did not labor. Others have labored, and you have entered into their labor.”

Matthew Henry Presbyterian @wholebiblehenry

We have here the remainder of the story of what happened when Christ was in Samaria, after the long conference he had with the woman. I. The interruption given to this discourse by the disciples' coming. It is probable that much more was said than is recorded; but just when the discourse was brought to a head, when Christ had made himself known to her...

Commenting on John 4:27-42

John Gill Reformed Baptist @doctorgill

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

Albert Barnes Presbyterian @notesbybarnes

Verse 38. I sent you. In the commission given you to preach the gospel. You have not labored or toiled in preparing the way for the great harvest which is now to be gathered in. Other men labored. (1.) The prophets, who long labored to prepare the way for the coming of the Messiah.