"They left that place and passed through Galilee. Jesus did not want anyone to know where they were, because he was teaching his disciples." NIV translation
Jesus wanted time alone with His disciples so that He could prepare them for what was ahead. His ministry in the vicinity was done and He was beginning the journey to Jerusalem. Just as the disciples needed time alone with Jesus to learn, we do as well so that we are prepared for what is ahead in our lives.
"He said to them, 'The Son of Man is going to be delivered into the hands of men. They will kill him, and after three days he will rise.' But they did not understand what he meant and were afraid to ask him about it." NIV translation
This is the second time that He predicted His death and resurrection. The disciples still did not see it as they were probably still caught up in their own thinking about the Messiah and the kingdom He would establish. They were afraid to ask Jesus to explain it more. That is why it is so important for us to let the Holy Spirit speak to us through the study of God's word.
"They came to Capernaum. When he was in the house, he asked them, 'What were you arguing about on the road?' But they kept quiet because on the way they had argued about who was the greatest." NIV translation
The disciples were so close to Jesus and yet they were still just men. On the way to Capernaum, they had argued about who was the greatest. It is interesting to note that Jesus knew that they were arguing but did not stop on the road to settle the matter. When He asked them about it, they were ashamed and kept quiet.
"Sitting down, Jesus called the Twelve and said, 'Anyone who wants to be first must be the very last, and the servant of all.' He took a little child whom he placed among them. Taking the child in his arms, he said to them, 'Whoever welcomes one of these little children in my name welcomes me; and whoever welcomes me does not welcome me but the one who sent me.'" NIV translation
Jesus answered their question by using the example of a little child. A child cannot give anything in return for helping them except love. A man that will serve those who cannot do anything for him is held in the highest regard by Jesus. God knows our hearts and can see whether we are doing things out of love or in hopes of personal gain.