Matthew follows Mark closely. He seems in vss. 37 and 38 to be quoting from his own account of the previous feeding. This item brings out a tendency of Matthew to repeat in one place phrases which he has used in another.
THE DEMAND FOR A SIGN
(Mk viii, 11-13; Mt xii, 38-39; Mt xvi, 1-4; Lk xi, 29; xii, 54-56)
Doublets in both Matthew and Luke indicate the presence of this section in both Mark and Q.[36]
THE SAYING ABOUT YEAST
(Mk viii, 14-21; Mt xvi, 5-12)
Matthew omits the rebuke to the disciples in Mark (viii, 17, 18). He apparently manufactures a saying of Jesus in his vs. 11, in order to introduce therewith his own editorial statement of vs. 12.
THE CONFESSION OF PETER AND THE FIRST PREDICTION OF SUFFERINGS
(Mk viii, 27-33; Mt xvi, 13-23; Lk ix, 18-22)