Three yanas leading from the origin
Three Outer Yanas Leading from the Origin (Tib. kun 'byung 'dren pa'i theg pa gsum) The three causal vehicles of characteristics are: the shravaka vehicle, pratyekabuddha vehicle and bodhisattva vehicle.
Why are these three called ‘vehicles leading from the origin’? It is because they lead us along the path to the result of liberation from samsara by abandoning all the actions (karma) and kleshas which are the cause or ‘origin’ [of suffering].