Bring 120 orbs to the oracle is a name given to six missions in The Precursor Legacy that Jak and Daxter complete to obtain power cells. Oracles each hold two power cells each (one for each eye), but were only willing to part with them for 120 Precursor orbs each. Each oracle releases cryptic messages as to "the light within" Jak, Daxter's change by dark eco, and hints to the existence of light eco.
When going from Sandover Village to the Forbidden Jungle, you will pass over a small beach with a stone pillar on the right. Climb the pillar and the oracle will be visible close by, on a small path next to the cliff. Roll jump ( while walking + ) from pillar to pillar to reach it.
Walk out from the Red Sage's hut and turn left. Go along the path and once you reach the last ledge turn around and go below the platforms you just crossed. Move forward here past the gaps and find the oracle in a small alcove on the left.