Heighten + Earth Spell can get a spell being the equivalent of a 10th level spell for all level-dependant purposes except it takes a 9th level slot. Using Silent Image and Shadowcraft Mage, you can replicate any Sorcerer/Wizard Evocation, Conjration (Summoning), and Conjuration (Creation) spell up to 9th level, but you only have the casting time and components of Silent Image. Using Arcane Disciple (Luck), you get Miracle added to your class spell list (assuming at least a 19 Wis, but that's easy to get). Since it's an Evocation and now on the Sorcerer/Wizard spell list (assuming you are a Sorcerer or Wizard), it's a fair target to mimic with Silent Image. Since you aren't actually casting Miracle, you don't care about its components (such as the XP cost).
I don't know why Innate Spell is in there, myself.