Jesus knows that he only has a couple of days left with his disciples, and he is giving them some final things to remember and look out for before he goes.
It’s always been interesting to me that only the Father knows when Jesus will come again. We know that the Father, the Son and the Holy Spirit are One, the three parts of the Trinity, the Triune God, but they are also three distinct entities. It’s a mystery that they evidently didn’t share this particular piece of knowledge.
As is often the case in instances that are difficult for us to understand, theologians through the ages disagree as to whether it was only the human part of Jesus that did not know, or that as God he knew but had not been given the authority as man to tell it to the disciples.
Also, it’s interesting to note that these words from Jesus only appear here in Mark.
Are there things that were revealed to Jesus as He grew? Did He have all knowledge at the moment of His birth, or did God the Father reveal things to Him as He matured? When He was a little boy, did He know that He would one day hang on a cross? Did He know that He was from the beginning? Did He remember creating the Heavens and the Earth? When He broke bread, did He think of His broken body?
None of us know for sure. All we can do is be thankful that however Jesus the man knew His mission, He went forward and did what God the Father asked Him to do. If He had not, your eternity and mine would be very dark, indeed.