The baptism of John
 The doctrine of which he was the first preacher, and the ordinance of which he was the first administrator: 
 was it from heaven, or of men?
 was it of divine or of human institution? 
 answer me;
 directly and plainly, without any shuffling, or evasion: it is a fair question, and may be answered; and the answer to it our Lord suggests would naturally lead to a proper one to their question; (See Gill on Matthew 21:25).