The fifth visuddhi is Purification of Knowledge and Vision of Path and Non. Path visuddhi). In this stage of insight, you get very good experiences; lightness, happiness, tranquility, serenity etc. Sometimes you may feel your body has become light, as if it has been lifted, or as if you were flying in the sky. Your mindfulness is very keen. Your effort is steady; neither slack nor vigorous, nor rigid. Your effort is moderate, steady and firm. Your concentration is deep, so you experience peace, calmness, serenity, tranquility, happiness, rapture and so on. This is a very good stage that meditators must go through.
This stage may be experienced in about two weeks if meditators practise strenuously, but some meditators go through this stage within a week. With such good experiences, meditators may think This must be nibbana- this is great, I have never experienced it before, it is better than having a million dollars - now I have attained nibbana Thus, he does not go further because he is clinging to it. He thinks that if he goes further, he will go beyond nibbana. If a meditator holds that this stage is nibbana, this is the wrong path. Therefore, he must continue to meditate and practise strenuously. This is only a very minor and trivial experience and he should not be content with it, but must go ahead with his practice.