Notice the Master's tender considerateness, Mark 8:1-9. He would not have the people faint on their way home. There are distinct differences between this miracle and the feeding of the five thousand. Most of these are evident to the English reader, but that between the baskets used for the fragments is clear only from the original-those used in the case of the five thousand being quite different from the large ones used here, Mark 8:20; Matthew 15:37. Our Lord never repeats His work.
The Savior sighed in the previous chapter over physical need; here He sighs over moral obtuseness, Mark 8:10-21. The language is very strong, and gives a glimpse into the Redeemer's heart. Had the Pharisees been as willing to discern the signs of the age as to read the weather, they must have been able to recognize Him and His claims; but their foolish heart was darkened. Having sighed over the hard-heartedness of the Pharisees, might He not equally have done so over the obtuseness of the Twelve? They thought that He was referring to their carelessness in omitting to take bread. How little they realized that the cause lay far deeper! Let us be quick to read the divine intention in very simple incidents, and to learn that all God's past dealings contain lessons for the present! [source]
Chapter Summary: Mark 8
1Jesus feeds the people miraculously; 10refuses to give a sign to the Pharisees; 14admonishes his disciples to beware of the leaven of the Pharisees and Herod; 22gives a blind man his sight; 27acknowledges that he is the Jesus who should suffer and rise again; 34and exhorts to patience in persecution for the profession of the gospel
Greek Commentary for Mark 8:21
Do ye not yet understand? [ουπω συνιετε] After all this rebuke and explanation. The greatest of all teachers had the greatest of all classes, but he struck a snag here. Matthew 16:12 gives the result: “Then they understood how that he bade them not beware of the loaves of bread, but of the teaching of the Pharisees and Sadducees.” They had once said that they understood the parables of Jesus (Matthew 13:51). But that was a long time ago. The teacher must have patience if his pupils are to understand. [source]
Greek Commentary for Mark 8:21
After all this rebuke and explanation. The greatest of all teachers had the greatest of all classes, but he struck a snag here. Matthew 16:12 gives the result: “Then they understood how that he bade them not beware of the loaves of bread, but of the teaching of the Pharisees and Sadducees.” They had once said that they understood the parables of Jesus (Matthew 13:51). But that was a long time ago. The teacher must have patience if his pupils are to understand. [source]