And a great multitude followed him, because they saw his miracles which he did on them that were diseased. They saw his miracles which he did - John does not mention these miracles; but Matthew details them, Matthew 12:2-14. John seems more intent on supplying the deficiencies of the other evangelists than in writing a connected history himself.
Related Commentaries of John 6:2
John 6:2
2 And a great multitude followed him, because they saw his miracles which he did on them that were diseased.