Albert Barnes Commentary John 18:6

"When therefore he said unto them, I am [he], they went backward, and fell to the ground." — John 18:6 (ASV)

They went backward, etc. The cause of their withdrawing in this manner is not mentioned. Various things might have produced it.

The frank, open, and fearless manner in which Jesus addressed them may have convinced them of his innocence and deterred them from prosecuting their wicked attempt. His disclosure of himself was sudden and unexpected. While they perhaps anticipated that he would make an effort to escape, they were amazed at his open and bold profession.

Their consciences reproved them for their crimes. Probably, the firm, decided, yet mild manner in which Jesus addressed them, an expression of his unequalled power in knowing how to find the way to the consciences of men, made them feel that they were in the presence of more than mortal man.

There is no proof that any miraculous power or mere physical force was present here. To suppose that there was greatly detracts from the moral sublimity of the scene.