How did the man enter Paradise even though the Day of Resurrection has not yet occurred?

The Prophet, peace and blessings be upon him, spoke of many matters concerning the Day of Judgment in the past tense, such as the Hadith of the man who watered a dog and entered Paradise, and the Hadith of Paradise and Hell being shown to him. This can be attributed to one of two interpretations: The first is that he saw them with his own eyes, as Allah Almighty removed the veils between him and them. The second is that it was a vision of knowledge and revelation, through Allah informing him and making him aware of their details. Or, he spoke of them in the past tense because their occurrence in the future is certain, just as Allah Almighty says: "The command of Allah has come, so do not hasten it."