What is the most important insight Momaday gains during his pilgrimage from Yellowstone to his grandmother gave at the Rainy Mountain? Include one quote.

The sadness in his grandmother's prayers that was passed down to him; Example: "I never understood her prayers, but there was something inherently sad in the sound"

true. the definition explains it: a word or phrase that modifies or qualifies an adjective, verb, or other adverb or a word group, expressing a relation of place, time, circumstance, manner, cause, degree, etc. this is a dictionary definition that i have looked up in a dictionary.