It is, Shaggy, but it sure doesn't feel 3000 years old to me. Come on. Let's go to the school lab and test it.
7 seconds sound clip from Scooby-Doo, Where Are You! - Scooby Doo and a Mummy, Too (S1E12).
You can hear this line at 00:10:54.841 in the Blu-ray version of the episode.
Quote context
[...]
- Hey, look over there! Isn't that Dr. Najib's car?
- Yeah. I thought he left hours ago.
- Is he...
- He's turned to stone! Poor Dr. Najib! He must have met the mummy before he could leave.
- I wonder if Shaggy and Velma met him yet.
- He's gone! The mummy's gone!
- And, like, he didn't even wait till we found Fred and Daphne.
- Well, at least he left his calling card.
- It looks more like a piece of that tape he's all wrapped up in to me.
- This test will tell us just how old that tape really is.
- Well, come on. Like, hurry. This place makes me so nervous all I can think of is food.
- Me, too!
- Now, let's see. Where is the potassium disulfate?
- Uh-oh! I wish I hadn't seen what I think I saw!
[...]