Some teachers say that the meditation practice without the Vinaya is very limited on its achievments.
Yes ofcourse.Sila is the foundation for Meditation.Monastics live in an environment that is conducive to meditation practice.Monastics also have rules that when followed significantly purifies their conduct compared to a lay person.
Can anyone explain what is the real difference?
Monastics follow 227/311 Precepts...I Need to realize Nibbanna in this Lifetime.
Lay People follow 5/8/10 Precepts...I need to realise Nibbanna in this lifetime or one day but in the mean time i don't want to fall in the lower realms.
The difference would be the sense of urgency.
What gets limited by not following Vinaya?
When we meditate we are purifying our minds..which is subtle.
When we train our sila we are purifying our actions..which is gross/course.
You can not expect to purify something that is subtle if you have a hard enough time purifying something that is course.
That is equivalent of saying that lay meditators will have very limited results, even if he/she keeps the 5 precepts.PS: The teacher was Ajahn Chah, he was talking about retreat, even in retreat the lay person wont get so far because of Vinaya, there is only so much a lay men can develope in meditation (even in a retreat).
That is true if you only see things in the context of this lifetime.But if you consider the infinite numbers of past lives we've had,whose to say in the past we we weren't monastics and the monastics weren't lay people .Lay people who realized Nibbanna didn't just achieve that out of the blue.They have cultivated and accumulated paramis in the past whether it be Sila or Renunciation and all they had to do now as a layperson is listen to a sentence or two of a Dharma Talk and thats all it takes.A gentle nudge.They were done as far as samsara is concerned.
So don't think that your practice is limited simply because your not following 311 precepts.You might have followed it maybe ten times in the past.Now maybe you just need an extra hour of vippasanna.Whose to say..