On November 30, 2017 an article was posted on the official site about stack interaction. There was a section I found misleading or confusing and was hoping someone could explain. I will copy and paste the section here and post a link to the original article at the end of my post. FYI, this section is specifically about responding to your own spells.
"Let's say you cast Sacred Mesa and have six mana left. But you're worried your opponent might have a card that you can't respond to because of its split second ability: Krosan Grip.
Well, you can activate the Mesa's ability in response to itself before your opponent ever gets the chance to respond! You're then guaranteed three Pegasus tokens even if they do have the Grip."
I know in order to active the ability of a permanent, such as Sacred Mesa, it needs to be on the field. How would one activate it's ability in response to itself while it is still on the stack?
"In response to itself" is a misleading way to say this, but it is in fact correct that you can activate the Mesa's ability three times before it's ever under threat of being destroyed in this situation. Once the spell resolves you continue to have priority until you pass and you're allowed to respond to your own abilities first as you keep priority (CR 116.3b-c); this means you can make three activations with no interruptions.