He who reaps receives wages, and gathers fruit to eternal life; that both he who sows and he who reaps may rejoice together.
Rejoice together ...  Sowers and reapers alike rejoice in the harvest of the gospel; and their doing so together would indicate that, in the instance in hand, sowing and reaping would occur in the closest proximity of time, as it did on that occasion.  Jesus was the sower who planted the word in the heart of the woman; but the fruit was coming over the fields at that very moment; and the apostles, who hardly knew that any sowing had taken place, were about to participate in the reaping.  Evidently, the Lord intended in these words to show the equal importance of both sowing and reaping, both being necessary, and to show that the reaper should always, in humility, remember the one who had sown.  That Christ was indeed the sower here is indicated by "He that soweth the good seed is the Son of man"  (Matthew 13:37).