So while y'all wait patiently for the next page, here's an excerpt from this world's equivalent of a college textbook for mages-in-training explaining the basics of magical foci such as staves, wands and tomes.

Most spells can be cast almost as immediately as the mage has finished incanting the runes required, during which time they should have gathered enough mana to cast it; but with the use of a focus, they can intentionally draw out the cast (or pre-cast by channeling before they begin chanting) to increase the amount of mana used for the eventual release.