Albert Barnes on Matthew 26:54

But how then shall the Scriptures be fulfilled, etc. That is, the scriptures which foretold of his dying for the world. In some way that must be accomplished; and the time had come when, having finished the work which the Father gave him to do, it was proper that he should submit to a cruel death. This was said doubtless to comfort his disciples; to show them that his death was not a matter of surprise or disappointment to him; and that they, therefore, should not be offended and forsake him.

(x) "that thus" Lk 24:26,46