The enemies of "man" are his sins, his carnal propensities, his lusts, and the great adversary Satan and his angels, who continually seek to destroy him. From "these" the Messiah came to save us.
This certainly was the mind of the Spirit that now inspired Zacharias, as appears by the whole tenor of Scripture; but whether he fully understood his own words is impossible for us to say. It is certain the older prophets, in some cases, did not fully understand the prophecies which they themselves uttered.
[Excerpts from Barne's Notes on the Bible & the Benson Commentary]