Through much of Matthew’s gospel, Jesus is surrounded by multitudes who marvel at His teaching and works (5:1; 7:28; 9:8; 12:23; 13:2; etc.).  They marvel all the way up to His battles in the temple (21:46; 22:33).  The last time He teaches a multitude is in chapter 23 (v. 1).

After that, Jesus is progressively isolated.  First one, then all the disciples leave Him.  And Matthew begins using the word “multitude” not to describe the adoring throngs but for the mob that comes with clubs to arrest Jesus and then for the crowds whipped up to demand His crucifixion (cf. 26:47, 55; 27:15, 20, 24).