If we continue with our practice, we will come to the borderline in a short time. In two or three thought moments we have reached the line and stand on it. The border here means the border between an ordinary person (puthujjana) and a Noble One (ariya). When you are on the boundary, do you want to go ahead or go back? If you want to go back, your attentions towards the past, but if you want to go ahead your attention is ahead. Ahead is the cessation of compounded things, i.e. the cessation of all kinds of mentality (nama) and physicality (rupa). If you want to proceed, standing on the boundary or border, you look ahead as well as behind. Then you will know, "If I go ahead, all kinds of suffering will cease to exist. So should I go ahead?" You will think about it. The answer is yes, because you have been suffering for many aeons (kappas). The word kappa means countless numbers of existences. When you are at the boundary, you will reflect on your past experiences, "I have been suffering for countless existences in this cycle of dukkha. Ive had enough of this I must put an end to this suffering."
Your attention is then towards the cessation of suffering. That borderline knowledge is known as Gotrabhu nana. Gotra means Puthujjana or descendants. On this border, descendants of a Puthujjana are cut off totally. Then there is no more Puthujjana. Once you pass that borderline, you become a Noble One (Ariya) because you have cut off the Puthujjana lineage. Venerable Nyanaponika Thera translates it as maturity knowledge or knowledge of maturity because the meditators knowledge is mature enough to attain the path. Actually, we can translate it literally as the knowledge which has cut off the Puthujjana lineage. When the Puthujjana lineage has been cut off, the meditator has attained Sotapatti magga nana - he becomes a Noble One, an Ariya.
Immediately after the borderline knowledge of maturity, there is Path Knowledge (Magga nana) which realises the Four Noble Truths thoroughly:
- Dukkha sacca The Truth of Suffering
- Samudaya sacca The Truth of the Cause of Suffering
- Nirodha sacca The Truth of the Cessation of Suffering
- Magga sacca The Truth of the Way Leading to the Cessation of Suffering