Source: "Pocket Monsters" fansub
*starts at about the 45 minute instant*
>Satoshi: "What's wrong?"
>Masato: "I'm never going to see Jirachi again."
>Satoshi: "The next time you'll see him is a thousand years from now. Better have a long life, now."
>Masato: "A thousand years is impossible!"
>Satoshi: "For a comet, a thousand years could be just an instant. That's what Takeshi said, at least. So maybe the thousand years Jirachi is asleep are just an instant for him. But it won't be like this, traveling around with us… For Masato or Jirachi… Not an 'instant' so to speak… Um, I can't say it very clearly…"
