The Nine Devices

I was reading The Lotus Sutra the other day and I came across Shakyamuni referring to "nine devices" as a way of teaching and leading people towardsed "the great vehicle", but upon looking the term, "the nine devices" up on the internet, I didn't find anything about the nine devices that he was refering to in the Lotus Sutra. Below is the passage it came from: > Here, the Buddha is preaching to Shariputra and a croud of nearly all of his deciples during the first of the three meetings in two places. "For those of dull capacities who delight in a lesser teaching, who greedily cling to birth and death, who, despite the innumerable buddhas, fail to practice the profound and wonderful way but are perplexed and confused by a host of troubles- for those I preach nirvana. I devise these expedient means and so cause them to enter into the buddha wisdom. Up to now I have never told you that you were certain to attain the buddha way. The reason I never preached in this manner was that the time to preach had not yet come. But now is the very time when I must decisively preach the great vehicle. **I use these nine devices**, adapting them to the living beings when I preach, my basic aim being to lead them to the great vehicle, and that is why I preach this sutra (68*). He then goes on to other related topics, but doesn't say what the nine devices are. Does anyone know? Are they referenced in another sutra? *This refers to page 68 in the Burton Watson translation of The Lotus Sutra.