Edgar is still disguised as Poor Tom, but he is now better dressed — as a peasant rather than a pitiful soul covered only in a blanket. More importantly, the manner in which he addresses his father indicates compassion, understanding, and an acceptance of his father's flaws. Edgar has forgiven Gloucester, and his voice reflects the sentiment. Shakespeare signifies the change by having Edgar speak in verse, so the audience is also aware that Edgar is not the same man he was earlier in the play.
Just before he intends to jump, Gloucester acknowledges the strength of the gods, whose justice he earlier questioned, and he prays that Edgar will be blessed. This scene is heart-rendering because Edgar does not reveal his identity. Instead, he permits the deception to continue so that Gloucester can be healed. When Gloucester awakens, he immediately questions if he actually fell, but then quickly resigns himself to his survival. Gloucester then accepts his afflictions and promises to endure until such time as the gods determine that he has suffered long enough.
Edgar states prior to Gloucester's "fall" that he will not disclose his true identity so that his father might still be cured, but there is ample opportunity after Gloucester awakens to divulge the secret, and yet, Edgar fails to tell Gloucester the truth. Gloucester's ignorance may be necessary for his continuing self-discovery. If Edgar reveals himself in Act IV, Gloucester's opportunities for growth will be cut short, and a major element of the play is the manner in which each character evolves in response to the circumstances that test his/her beliefs, values, and strengths. Gloucester must continue to learn about himself; his movement toward self-truth would be halted if he resolves his conflict with Edgar at this point.
