By Mr. Brian P. David
This verse shows the Lord preparing to deliver the Sermon on the Mount, among the most famous and most quoted passages of the Bible. Understood on a spiritual level, this verse shows the real nature of those preparations.
A "multitude" represents a collection of ideas and knowledge about spiritual things. To "go up" represents an elevation in spiritual state, and a "mountain" represents the Lord's perfect, infinite, divine love for humanity. "Disciples," in an abstract sense, represent the desire for good and understanding of truth that come from the Lord.
It is early in the Lord's ministry. He has gathered disciples and traveled Galilee preaching and healing, but this is his first big public statement. So we can see how he regarded the "multitude" – the ideas he had been sharing – and then rose up into a state of pure love. From that vantage point, He looked at the ideas again, ready to express them in more depth from the fulness of His love.