The Great Prajna Paramita Sutra, Volume 6 - Bog

When staying with prajna paramita, the bodhisattva-path practitioners will also absorb all superior virtuous dharmas. Owing to nonattainment, learners will be relieved from attachment and self-conceit and become humble, and their powers for removing vexations, hindrances, coverings, and bondages will also be strengthened. That is what is meant by expedient skillfulness in cultivating prajna paramita.
The importance of the bodhisattvas becomes significant during the times when Thus-Comers are not present. Given that circumstance, the bodhisattvas are the only ones who can teach sentient beings correct dharma expediently and skillfully. Both great bodhisattvas and expedient skillfulness come out of prajna paramita. Because the great bodhisattvas have achieved expedient skillfulness, they are able to really practice virtuous dharmas, attain superior benefits, assist the sentient beings to mature, and dignify and purify the Buddha lands.