No where said. The context is very clear according to the second clause that his fate is to this world by sending Skirk to teyvat.
Literally the second clause: Indeed, you shall send your disciple here in the near future." And by this sense his fate is to this world.
—Vedrfolnir "The Visionary" & Surtalogi "The Foul"
And again Vedrfolnir can't be wrong.
That is cope when both English and Cn says the exact same lol. No one means no one
「罪恶侵染天幕,灾劫蔓延整个宇宙,再无人能限制你的自由。但你的命运仍与这个世界息息相关,就像不远的将来,你会将自己的弟子送到这里。」
“Evil taints the heavens, and calamities spread throughout the universe—
no one can restrict your freedom anymore. Yet your fate remains deeply intertwined with this world, just as in the near future, you will send your disciple here.”
Sin infests the firmament, calamity unfurls across the universe.
You are free, and none now may proscribe you — yet your destiny remains bound to that of this world. Indeed, you shall send your disciple here in the near future."
"What? Me, a student? Such misfortune — for them, I mean... whenever they show up."
—Vedrfolnir "The Visionary" & Surtalogi "The Foul"