III. They prove the Resurrection of the flesh
And in the course of these and other miracles, when the disciples were harassed by bewildering thoughts, and the Lord had appeared in their midst and said, “Peace be unto you,” that what was passing through their hearts might not be their fixed opinion (for they thought they saw a spirit not flesh), He refutes their thoughts so discordant with the Truth, offers to the doubters' eyes the marks of the cross that remained in His hands and feet, and invites them to handle Him with careful scrutiny, because the traces of the nails and spear had been retained to heal the wounds of unbelieving hearts, so that not with wavering faith, but with most steadfast knowledge they might comprehend that the Nature which had been lain in the sepulchre was to sit on God the Father's throne.
Source: Sermons (New Advent)