No, the word "gotrabhu" occurs in a Sutta passage with unclear meaning but probably just meaning "a member of the Sangha". Later the Abhidhamma and commentaries develop a theory in which gotrabhu is one of the preliminary stages to awakening. The Thai forest teachers get the idea from there and, based on their own experience, talk about such a stage in one's practice. For example:
Samādhi means the mind that is firmly concentrated, and the more you practise the firmer the mind becomes. The more firmly the mind is concentrated, the more resolute in the practice it becomes. The more you contemplate, the more confident you become. The mind becomes truly stable - to the point where it can't be swayed by anything at all. You are absolutely confident that no single mind-object has the power to shake it. Mind-objects are mind-objects; the mind is the mind. The mind experiences good and bad mental states, happiness and suffering, because it is deluded by mind-objects. If it isn't deluded by mind-objects, there's no suffering. The undeluded mind can't be shaken. This phenomenon is a state of awareness, where all things and phenomena are viewed entirely as dhātu11 (natural elements) arising and passing away - just that much. It might be possible to have this experience and yet still be unable to fully let go. Whether you can or can't let go, don't let this bother you. Before anything else, you must at least develop and sustain this level of awareness or fixed determination in the mind. You have to keep applying the pressure and destroying defilements through determined effort, penetrating deeper and deeper into the practice.
Having discerned the Dhamma in this way, the mind will withdraw to a less intense level of practice, which the Buddha and subsequent Buddhist scriptures describe as the Gotrabhū citta12. The Gotrabhū citta refers to the mind which has experienced going beyond the boundaries of the ordinary human mind. It is the mind of the puthujjana (ordinary unenlightened individual) breaking through into the realm of the ariyan (Noble One) - however, this phenomena still takes place within the mind of the ordinary unenlightened individual like ourselves. The Gotrabhū puggala is someone, who, having progressed in their practice until they gain temporary experience of Nibbāna (enlightenment), withdraws from it and continues practising on another level, because they have not yet completely cut off all defilements. It's like someone who is in the middle of stepping across a stream, with one foot on the near bank, and the other on the far side. They know for sure that there are two sides to the stream, but are unable to cross over it completely and so step back. The understanding that there exist two sides to the stream is similar to that of the Gotrabhū puggala or the Gotrabhū citta. It means that you know the way to go beyond the defilements, but are still unable to go there, and so step back. Once you know for yourself that this state truly exists, this knowledge remains with you constantly as you continue to practise meditation and develop your pāramī. You are both certain of the goal and the most direct way to reach it.http://www.ajahnchah.org/book/Path_Peace.php
Emptiness means that we have seen the reality of the material world. The mind is different from the body, distinct and absolutely separate. One can compare it to going to another world, having the feeling of witnessing another world - not the world of conventions, not the world of the I or me, not the world of beings, persons, me and mine, us and them. It is a world that exists of freedom. The mind definitely flies up heading towards it, but cannot reach it yet. It has to return again, back to the conventions. But at least, when we have come as far as this, we will know, that if we keep investigating in this direction many times and get to see things clearly many times, then we should be able to see the Dhamma, realize the Dhamma. This knowledge of the possibility of advancing into freedom is called gotrabhu- nyana. Comparing it to the rocket, it means that our rocket has left the field of gravity of this world and is heading on to another universe. The third stage has already given it the power to shoot on and on. At this stage we are very inspired to practise. Nobody has to remind us to put forth effort, to do walking meditation or sitting meditation, we want to do it by ourselves. http://www.dhammatalks.net/Books5/Ajahn ... ration.htm