Translation
Because of this you also must be prepared
for the SON OF MAN
comes in that hour when you do not expect it.
Paraphrase
Likewise, you must be spiritually alert and open minded about the way I work or you will miss what I do;
for I, GOD’S ANSWER TO MAN’S PROBLEM, will show up on the scene when you least expect it.
“When You Do Not Expect It"
I believe there was more in view here than just the timing of His glorious arrival, rather pertained to the manner in which He will show His power. The disciples had asked a “when” question, so Jesus’ answer is couched in the context of “when,” but the reason for His answer has to do with other things, not just timing. All along the disciples were waiting for Jesus to do things they expected the Messiah would do, and all along Jesus did things in ways they were not expecting. By this statement He was signaling to them that He would continue to work in ways that would surprise them, that is why they needed to be watchful. By saying “be watchful” he meant “Keep an open mind and watch for me to do things in ways you would not ordinarily have expected.”