Is repentance sufficient to avoid being afflicted with the same physical defect as a colleague, after mocking him?

Calamity is tied to speech. Thus, whoever mocks someone with a disability or in a poor state might be afflicted with the very thing they ridiculed. The predecessors went to great lengths to guard against this, to the extent that Ibn Mas'ud said: "If I were to mock a dog, I would fear being transformed into a dog." If you repent from this sin, then praise Allah for your repentance and increase in acts of obedience and supplication.