“I have compassion on the crowd because they continue with me now three days and have nothing to eat, and if I send them away fasting to their home they will faint in the way, and some of them are come from far.”
Here it is Jesus Who expressed concern for the lack of food, while in chapter 6 it was the disciples. He had preached to them and had no doubt done many healings over the three days and He knew that now their food supplies were gone. And He knew that many had come long distances and in His compassion was afraid that if they returned home without food they would not be able to make the journey.
We note that here His compassion is expressed for their lack of food. In chapter 6 they had only had one day without sufficient food and His concern was more for their spiritual need, but here their physical need was greater and thus He had concern for that. Jesus was concerned for the whole man and his needs.
The crowd was presumably a mixture of Jews and Gentiles. When such a wonder worker was at work it was unlikely that Gentiles would keep away, and Mark (and undoubtedly Jesus) has this very much in mind.