This was from 1990. But some points of the novel Cyber Way by Alan Dean Foster seem to match your description.
It is a near future science fiction murder mystery in which the tech savvy protagonist ends up partnering with a Navajo to unravel how a traditional sand painting figures into the murder of wealthy art collector. He ends up discovering an alien presence (the energy being you mention).
The Apache phrase:
"Well, you won't meet many Hopis, so don't worry about that. They have their own commercial center over at Seba Delkai. The Zunis stick mostly to New Mexico. But if you have trouble with any Navaho, just smile and say 'doo ahashyaa da.'"
"Do a hashee dun," Moody essayed. Ooljee repeated the phrase slowly and carefully until he was sure Moody had it reasonably correct.
And, from the Author's Notes:
The Navaho phrase "doo ahashyaa da" means "I am stupid."
Some additional comments at: Amazon link