‘Now there went with him great crowds, and he turned, and said to them,'
Great crowds ‘went on together with Him', as He went on His way to Jerusalem, and they included many would be disciples who were not aware of why He was going there. For in the crowds would be people with different hopes. Some loved to hear Jesus' stories, others were convinced that He was a great prophet, still others wondered whether He was the Messiah biding His time, and still others were full of enthusiasm and were considering following Him fully.
But Jesus did not want men to follow as disciples unless they had counted the cost. They could believe on Him, and commit themselves to the Kingly Rule of God without doing so. But for them to become His disciples and follow Him involved an extra cost, and He wanted to ensure that if they did follow Him they had taken this into account. So He wanted to warn them what discipleship might involve.