And the people asked him, saying, What shall we do then? Dean Plumptre's note here is interesting and suggestive: "The questions that follow are peculiar to St. Luke. They are interesting as showing that the work of the Baptist was not that of a mere preacher of repentance.
Confession of sins followed naturally on the part of the penitents; that was followed, as naturally, by guidance for the conscience. St. Luke, as a physician of the soul, may well have delighted to place on record this example of true spiritual therapeutics."
The same train of thought is followed out by Godet in his remark on the question contained in this verse: "It is the confessional after preaching." This little section (verses 10-14), containing an epitome of questions placed before John by different classes of hearers touched by his soul-stirring preaching, is peculiar to our evangelist.
It is clear that here, in the story of the ministry of the Baptist, Luke derived his knowledge of the details from an independent authority not used either by Matthew or Mark.