Just as with spells, the very first thing that happens when you announce an activated ability is that the ability is placed on the stack. After making any required choices and determining the cost, you pay that cost.
So you announce that you’re activating Birthing Pod, and its ability goes on the stack. Then you declare that you’re going to pay 1 mana and 2 life, tap the Pod, and sacrifice your Solemn Simulacrum, and you do all that. Now the Solemn triggers, and the only place that triggered ability can go is on the top of the stack, above the Pod’s activated ability that has been on the stack for a little while already. So you have to hope you don’t draw that Acidic Slime or Zealous Conscripts you were planning to search for, because you don’t have a choice whether to search first or draw first; you must draw before you search.
Basic rule of thumb: Anything that triggers during the activation of an ability will resolve before the activated ability.
Today’s Rules Tip written by
Josh Stansfield, Level 2 judge from Orange, CA