The passage we consider here culminates in Christ’s rebuke of the disciples for their continued and ongoing hardness of heart. The picture we have of hardness in a believer is most instructive — provided we are not hard of heart ourselves.
Superficial critics think that this account is in Mark because of a confusion of one narrative evolving into two. But this neglects Mark’s very careful preparation for the confession given by Peter. This spadework is done twice, so that there can be no mistake. Note the parallel accounts: Feeding of the multitude (6:31-44; 8:1-9), crossing of sea and landing (6:45-56; 8:10), conflict with Pharisees (7:1-23; 8:11-13). conversation about bread (7:24-30; 8:14-21), healing (7:31-36; 8:22-26), and confession of faith (7:37; 8:27-30). These narratives are not side-by-side through any accident.
This crowd of four thousand most likely contains a large Gentile component. Remember the context — conflict with the Pharisees, kindness shown to the Syrophoenician woman, and now here, Christ including Gentiles in His provision. At any rate, the crowd was very great (v. 1), and Jesus mentions His concern for them lest they collapse on the way home (vv. 2-3).
The disciples are without a clue — they do not know how to respond, and ask, “How is it possible . . .?” (v. 4) Jesus asks, and it turns out they have seven loaves, along with a few fish (v. 5). Jesus gives the command for them all to sit down, and He multiplies the loaves, as before (v. 6), and He multiplies the fish, as before (v. 7). The baskets here are not the same kind as in the previous miracle, being much bigger. Instead of twelve small baskets filled, we now have seven large hampers filled. The four thousand who ate were filled and then sent away (vv. 8-9). The number twelve (as we have noted) corresponds to the formation of a New Israel. The number seven (throughout Scripture) is commonly connected to the idea of fullness or completeness. The provision for this New Israel will be ample, full, complete — a true sabbath provision.
Jesus then crosses the sea (v. 10), and the Pharisees challenge Him again, demanding a sign from heaven (v. 11). Note that they do not accept miracles, because they claim the miracles are from Satan. Jesus is exasperated by the demand (sighing deeply in His spirit), and flatly rejects their demand (v. 12). No sign will be given them but the sign of Jonah (according to Matthew), a sign which, when they received it, they rejected also. The Lord abruptly leaves them (v. 13).
They left so quickly that the disciples forgot to bring any fresh provisions with them. They noticed this, and were distraught over the lack of bread (vv. 14, 16). In the meantime, Jesus wanted the disciples to learn about the collision they had just had with the Pharisees, and so He was solemnly warning them about the leaven of false teaching (v. 15). Note in passing the importance of this lesson, and note the nature of the danger. It is quiet, unobtrusive, and anyone who obeys Jesus at this point will always look as though he is making a big deal out of nothing. Just the word leaven is enough to make the disciples think they are in trouble for not bringing bread (v. 16). In short, they are not listening; they are distracted by their various worldly concerns. Two things may be said about this distraction: first, it is silly. Jesus has just fed two multitudes from next to nothing. Could He not do the same for His disciples? Second, it is spiritually destructive, keeping the disciples from seeing what they needed to see.
That is why there is a rebuke — “Why do you think this way?” Jesus asks. He wants to know if their hearts are still hardened. What does such hardness of heart look like? On a smaller scale, it looks just like it did in the Pharisees — seeing but not seeing, hearing but not hearing. When Jesus asks them questions, they answer properly. They remember, but in the fundamental sense, they did not remember (vv. 17-21). What do we see, but fail to see? What do we hear, but fail to hear? What do we remember, but fail to remember? How many catechism questions do we answer in one sense, and flunk in another?