I need some help figuring out what this sound might be on a Jeep Grand Cherokee.

This is on a 2004 Jeep Grand cherokee 4.0. It doesn't do it when I brake/slow down, or when I'm driving at speed. Only does it when I accelerate. It also doesn't do it when I'm stopped and Rev the engine. (neutral). We put the car in neutral while driving and the sound wasn't there. It's only present when we accelerate.

I recently went and played in the mud a little. Nothing too crazy. I never had to leave 2WD

https://youtu.be/6gBBMZEgXVM