- Sarah, do you really mean it?
- I most certainly do!

6 seconds sound clip from the The Moon's Our Home (1941) classic radio play.

You can hear this line at 00:33:56 in the radio play.

Quote context

[...]

- I'm a little deaf. That's fine. I'll start the ceremony.

- Where did you get that license?

- Five days ago.

- You were that sure of me?

- Why, of course.

- And you have been since the beginning, haven't you?

- Well, certainly.

- After all this, do you still expect me to marry you?

- I do.

- Well, I wasn't taking any chances. Do you still think I was presumptuous?

- Do I?

- Sarah, do you really mean it?

- I most certainly do!

- You made a fool out of me long enough! Our marriage is off!

- Hey, wait a minute, wait a minute, wait a minute! Just a minute. Just a minute.

- What'd you say, mister?

- Man and wife! It's over, folks. Three dollars, please.

- After a short intermission, Mr. DeMille will return with our stars, Carole Lombard and James Stewart, for Act Three of 'The Moon's Our Home.'

[...]