{Till the Son of man be come} (he(9373) elth(8869) ho huios tou
anthr(9370)ou). Moffatt puts it "before the Son of man arrives" as
if Jesus referred to this special tour of Galilee. Jesus could
overtake them. Possibly so, but it is by no means clear. Some
refer it to the Transfiguration, others to the coming of the Holy
Spirit at Pentecost, others to the Second Coming. Some hold that
Matthew has put the saying in the wrong context. Others bluntly
say that Jesus was mistaken, a very serious charge to make in his
instructions to these preachers. The use of he(9373) with aorist
subjunctive for a future event is a good Greek idiom.