We've found it!
4 seconds sound clip from the Tangled movie soundboard.
You can hear this line at 00:02:48 in the Blu-ray version of the movie.
Quote context
[...]
- Ahhh, I told you she'd be important.
- And all she had to do, was sing a special song.
- Flower, gleam and glow, let your power shine, make the clock reverse, bring back what once was mine.
- All right, you get the jist. She sings to it, she turns young, creepy, right?
- The magic of the golden flower healed the queen.
- A healthy baby girl, a princess was born. With beautiful golden hair.
- I'll give you a hint. That's Rapunzel.
- To celebrate her birth, the king and queen launched a flying lantern into the sky.
[...]