Put it at the climax of a short edit, right after the selection is shown and before the celebration starts. Lead in with It Was At This Moment He Knew to set up the turning point, then follow with Hallelujah once the chosen person steps forward.
About this sound
This 19-second clip delivers the line 'Harry, you are the chosen one' as a slow, weighty piece of spoken movie dialogue, with the emphasis falling on the final words. It feels dramatic and earnest, like a turning point being announced, and it works best when the moment needs to feel bigger than an ordinary compliment or joke.