Bring 120 orbs to the oracle is the name of six missions in The Precursor Legacy that Jak and Daxter complete to earn power cells. There is an Oracle in each hub village, each with two power cells with which they would part for 120 Precursor orbs each. The Oracles would first deliver messages concerning Jak's fate and cryptic references to other things, such as light eco.
The required Precursor orbs can be collected from any location regardless of the location of the Oracle. Talking to the Oracle beforehand is also optional. Upon collecting at least 120 orbs, you exchange them for a power cell from any Oracle.
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.