It's a song with the lyrics "What's that? What's that? What's that? The river's clear, and it's sung by a girl.

It's "All Creatures Are Alive" sung by Sa Dingding! The lyrics are as follows:

Title: All Creatures Are Alive

Sung by: Sa Dingding

Lyrics: All Creatures Are Alive

Lyrics:

Once upon a time, the winter was cold, and the summer was rainy, and the water was clear.

Autumn, the sound of your voice came from far away and warmed my heart.

They said that there were white snows behind the houses.

There were golden flags in the valleys, and the water was clear.

There were golden flags in the valley that fluttered in the wind

I saw mountain eagles flying on two lonely fish

The two fish crossed a river as salty as the sea

A piece of the river fell and met the people broken

People were walking and covered with mountain eagle dust

Once upon a time, the winter was cold and the summer rained on us

Autumn came to us with your voice warming our hearts from afar. I saw a mountain eagle flying over two lonely fish

The two fish crossed a river as salty as the sea

A piece of the river fell and met the people broken

People walking were covered with mountain eagle dust

People walking were covered with mountain eagle dust

People walking were covered with mountain eagle dust

People walking were covered with mountain eagle dust

People walking were covered with mountain eagle dust

People walking were covered with mountain eagle dust

People walking were covered with mountain eagle dust

There was once a cold winter and a rainy summer. Ash

I saw a mountain eagle fly on two lonely fish

Two fish crossed a river as salty as the sea

A river fell and met people broken

People walking with the ash of a mountain eagle

I saw a mountain eagle fly on two lonely fish

Two fish crossed a river as salty as the sea

A river fell and met people broken

People walking with the ash of a mountain eagle

I saw a mountain eagle fly on two lonely fish

Two fish crossed a river as salty as the sea

A river fell and met people broken

People walking covered in mountain eagle dust

I see mountain eagles flying on two lonely fish

Two fish across a river as salty as the sea

A river falls and meets people broken

People walking covered in mountain eagle dust