A.T. Robertson Commentary Matthew 3:14

"But John would have hindered him, saying, I have need to be baptized of thee, and comest thou to me?" — Matthew 3:14 (ASV)

Would have hindered (διεκωλυεν). Rather "tried to prevent" as Moffatt has it. It is the conative imperfect. The two men of destiny are face to face for the first time apparently. The Coming One stands before John and he recognizes him before the promised sign is given.