John Gill Commentary Matthew 15:16

"And he said, Are ye also even yet without understanding?" — Matthew 15:16 (ASV)

And Jesus said
As wondering at, and as being displeased with, and as reproving them for their dulness and ignorance:

are you also yet without understanding?
you, my disciples, as well as the Scribes and Pharisees; you, who have been with me so long, who have heard so many discourses from me, who for so long a time have been instructed by me, both in private, and in public; and yet do not understand what is so plain and easy, that has nothing of difficulty in it, but what might easily be accounted for.